* Step 1: NaturalPI WORST_CASE(?,O(n^2))
    + Considered Problem:
        - Strict TRS:
            Concat(Cons_sum(xi,k,s),t) -> Cons_sum(xi,k,Concat(s,t))
            Concat(Cons_usual(x,m,s),t) -> Cons_usual(x,Term_sub(m,t),Concat(s,t))
            Concat(Id(),s) -> s
            Frozen(m,Sum_constant(Left()),n,s) -> Term_sub(m,s)
            Frozen(m,Sum_constant(Right()),n,s) -> Term_sub(n,s)
            Frozen(m,Sum_term_var(xi),n,s) -> Case(Term_sub(m,s),xi,Term_sub(n,s))
            Sum_sub(xi,Cons_sum(psi,k,s)) -> Sum_constant(k)
            Sum_sub(xi,Cons_sum(psi,k,s)) -> Sum_sub(xi,s)
            Sum_sub(xi,Cons_usual(y,m,s)) -> Sum_sub(xi,s)
            Sum_sub(xi,Id()) -> Sum_term_var(xi)
            Term_sub(Case(m,xi,n),s) -> Frozen(m,Sum_sub(xi,s),n,s)
            Term_sub(Term_app(m,n),s) -> Term_app(Term_sub(m,s),Term_sub(n,s))
            Term_sub(Term_inl(m),s) -> Term_inl(Term_sub(m,s))
            Term_sub(Term_inr(m),s) -> Term_inr(Term_sub(m,s))
            Term_sub(Term_pair(m,n),s) -> Term_pair(Term_sub(m,s),Term_sub(n,s))
            Term_sub(Term_var(x),Cons_sum(xi,k,s)) -> Term_sub(Term_var(x),s)
            Term_sub(Term_var(x),Cons_usual(y,m,s)) -> m
            Term_sub(Term_var(x),Cons_usual(y,m,s)) -> Term_sub(Term_var(x),s)
            Term_sub(Term_var(x),Id()) -> Term_var(x)
        - Signature:
            {Concat/2,Frozen/4,Sum_sub/2,Term_sub/2} / {Case/3,Cons_sum/3,Cons_usual/3,Id/0,Left/0,Right/0
            ,Sum_constant/1,Sum_term_var/1,Term_app/2,Term_inl/1,Term_inr/1,Term_pair/2,Term_var/1}
        - Obligation:
            innermost runtime complexity wrt. defined symbols {Concat,Frozen,Sum_sub,Term_sub} and constructors {Case
            ,Cons_sum,Cons_usual,Id,Left,Right,Sum_constant,Sum_term_var,Term_app,Term_inl,Term_inr,Term_pair,Term_var}
    + Applied Processor:
        NaturalPI {shape = Mixed 2, restrict = Restrict, uargs = UArgs, urules = URules, selector = Just any strict-rules}
    + Details:
        We apply a polynomial interpretation of kind constructor-based(mixed(2)):
        The following argument positions are considered usable:
          uargs(Case) = {1,3},
          uargs(Cons_sum) = {3},
          uargs(Cons_usual) = {2,3},
          uargs(Frozen) = {2},
          uargs(Term_app) = {1,2},
          uargs(Term_inl) = {1},
          uargs(Term_inr) = {1},
          uargs(Term_pair) = {1,2}
        
        Following symbols are considered usable:
          {Concat,Frozen,Sum_sub,Term_sub}
        TcT has computed the following interpretation:
                  p(Case) = x1 + x2 + x3                                            
                p(Concat) = 2*x1 + 2*x1*x2 + 2*x1^2 + 2*x2^2                        
              p(Cons_sum) = x3                                                      
            p(Cons_usual) = x2 + x3                                                 
                p(Frozen) = x1 + 2*x1*x3 + 2*x1*x4 + x1^2 + x2 + x3 + 2*x3*x4 + x3^2
                    p(Id) = 1                                                       
                  p(Left) = 0                                                       
                 p(Right) = 0                                                       
          p(Sum_constant) = 0                                                       
               p(Sum_sub) = x1*x2                                                   
          p(Sum_term_var) = x1                                                      
              p(Term_app) = 1 + x1 + x2                                             
              p(Term_inl) = x1                                                      
              p(Term_inr) = 1 + x1                                                  
             p(Term_pair) = 1 + x1 + x2                                             
              p(Term_sub) = x1 + 2*x1*x2 + x1^2                                     
              p(Term_var) = 1 + x1                                                  
        
        Following rules are strictly oriented:
                                 Concat(Id(),s) = 4 + 2*s + 2*s^2                                        
                                                > s                                                      
                                                = s                                                      
        
                      Term_sub(Term_app(m,n),s) = 2 + 3*m + 2*m*n + 2*m*s + m^2 + 3*n + 2*n*s + n^2 + 2*s
                                                > 1 + m + 2*m*s + m^2 + n + 2*n*s + n^2                  
                                                = Term_app(Term_sub(m,s),Term_sub(n,s))                  
        
                        Term_sub(Term_inr(m),s) = 2 + 3*m + 2*m*s + m^2 + 2*s                            
                                                > 1 + m + 2*m*s + m^2                                    
                                                = Term_inr(Term_sub(m,s))                                
        
                     Term_sub(Term_pair(m,n),s) = 2 + 3*m + 2*m*n + 2*m*s + m^2 + 3*n + 2*n*s + n^2 + 2*s
                                                > 1 + m + 2*m*s + m^2 + n + 2*n*s + n^2                  
                                                = Term_pair(Term_sub(m,s),Term_sub(n,s))                 
        
        Term_sub(Term_var(x),Cons_usual(y,m,s)) = 2 + 2*m + 2*m*x + 2*s + 2*s*x + 3*x + x^2              
                                                > m                                                      
                                                = m                                                      
        
                     Term_sub(Term_var(x),Id()) = 4 + 5*x + x^2                                          
                                                > 1 + x                                                  
                                                = Term_var(x)                                            
        
        
        Following rules are (at-least) weakly oriented:
                     Concat(Cons_sum(xi,k,s),t) =  2*s + 2*s*t + 2*s^2 + 2*t^2                                                     
                                                >= 2*s + 2*s*t + 2*s^2 + 2*t^2                                                     
                                                =  Cons_sum(xi,k,Concat(s,t))                                                      
        
                    Concat(Cons_usual(x,m,s),t) =  2*m + 4*m*s + 2*m*t + 2*m^2 + 2*s + 2*s*t + 2*s^2 + 2*t^2                       
                                                >= m + 2*m*t + m^2 + 2*s + 2*s*t + 2*s^2 + 2*t^2                                   
                                                =  Cons_usual(x,Term_sub(m,t),Concat(s,t))                                         
        
             Frozen(m,Sum_constant(Left()),n,s) =  m + 2*m*n + 2*m*s + m^2 + n + 2*n*s + n^2                                       
                                                >= m + 2*m*s + m^2                                                                 
                                                =  Term_sub(m,s)                                                                   
        
            Frozen(m,Sum_constant(Right()),n,s) =  m + 2*m*n + 2*m*s + m^2 + n + 2*n*s + n^2                                       
                                                >= n + 2*n*s + n^2                                                                 
                                                =  Term_sub(n,s)                                                                   
        
                 Frozen(m,Sum_term_var(xi),n,s) =  m + 2*m*n + 2*m*s + m^2 + n + 2*n*s + n^2 + xi                                  
                                                >= m + 2*m*s + m^2 + n + 2*n*s + n^2 + xi                                          
                                                =  Case(Term_sub(m,s),xi,Term_sub(n,s))                                            
        
                  Sum_sub(xi,Cons_sum(psi,k,s)) =  s*xi                                                                            
                                                >= 0                                                                               
                                                =  Sum_constant(k)                                                                 
        
                  Sum_sub(xi,Cons_sum(psi,k,s)) =  s*xi                                                                            
                                                >= s*xi                                                                            
                                                =  Sum_sub(xi,s)                                                                   
        
                  Sum_sub(xi,Cons_usual(y,m,s)) =  m*xi + s*xi                                                                     
                                                >= s*xi                                                                            
                                                =  Sum_sub(xi,s)                                                                   
        
                               Sum_sub(xi,Id()) =  xi                                                                              
                                                >= xi                                                                              
                                                =  Sum_term_var(xi)                                                                
        
                       Term_sub(Case(m,xi,n),s) =  m + 2*m*n + 2*m*s + 2*m*xi + m^2 + n + 2*n*s + 2*n*xi + n^2 + 2*s*xi + xi + xi^2
                                                >= m + 2*m*n + 2*m*s + m^2 + n + 2*n*s + n^2 + s*xi                                
                                                =  Frozen(m,Sum_sub(xi,s),n,s)                                                     
        
                        Term_sub(Term_inl(m),s) =  m + 2*m*s + m^2                                                                 
                                                >= m + 2*m*s + m^2                                                                 
                                                =  Term_inl(Term_sub(m,s))                                                         
        
         Term_sub(Term_var(x),Cons_sum(xi,k,s)) =  2 + 2*s + 2*s*x + 3*x + x^2                                                     
                                                >= 2 + 2*s + 2*s*x + 3*x + x^2                                                     
                                                =  Term_sub(Term_var(x),s)                                                         
        
        Term_sub(Term_var(x),Cons_usual(y,m,s)) =  2 + 2*m + 2*m*x + 2*s + 2*s*x + 3*x + x^2                                       
                                                >= 2 + 2*s + 2*s*x + 3*x + x^2                                                     
                                                =  Term_sub(Term_var(x),s)                                                         
        
* Step 2: NaturalPI WORST_CASE(?,O(n^2))
    + Considered Problem:
        - Strict TRS:
            Concat(Cons_sum(xi,k,s),t) -> Cons_sum(xi,k,Concat(s,t))
            Concat(Cons_usual(x,m,s),t) -> Cons_usual(x,Term_sub(m,t),Concat(s,t))
            Frozen(m,Sum_constant(Left()),n,s) -> Term_sub(m,s)
            Frozen(m,Sum_constant(Right()),n,s) -> Term_sub(n,s)
            Frozen(m,Sum_term_var(xi),n,s) -> Case(Term_sub(m,s),xi,Term_sub(n,s))
            Sum_sub(xi,Cons_sum(psi,k,s)) -> Sum_constant(k)
            Sum_sub(xi,Cons_sum(psi,k,s)) -> Sum_sub(xi,s)
            Sum_sub(xi,Cons_usual(y,m,s)) -> Sum_sub(xi,s)
            Sum_sub(xi,Id()) -> Sum_term_var(xi)
            Term_sub(Case(m,xi,n),s) -> Frozen(m,Sum_sub(xi,s),n,s)
            Term_sub(Term_inl(m),s) -> Term_inl(Term_sub(m,s))
            Term_sub(Term_var(x),Cons_sum(xi,k,s)) -> Term_sub(Term_var(x),s)
            Term_sub(Term_var(x),Cons_usual(y,m,s)) -> Term_sub(Term_var(x),s)
        - Weak TRS:
            Concat(Id(),s) -> s
            Term_sub(Term_app(m,n),s) -> Term_app(Term_sub(m,s),Term_sub(n,s))
            Term_sub(Term_inr(m),s) -> Term_inr(Term_sub(m,s))
            Term_sub(Term_pair(m,n),s) -> Term_pair(Term_sub(m,s),Term_sub(n,s))
            Term_sub(Term_var(x),Cons_usual(y,m,s)) -> m
            Term_sub(Term_var(x),Id()) -> Term_var(x)
        - Signature:
            {Concat/2,Frozen/4,Sum_sub/2,Term_sub/2} / {Case/3,Cons_sum/3,Cons_usual/3,Id/0,Left/0,Right/0
            ,Sum_constant/1,Sum_term_var/1,Term_app/2,Term_inl/1,Term_inr/1,Term_pair/2,Term_var/1}
        - Obligation:
            innermost runtime complexity wrt. defined symbols {Concat,Frozen,Sum_sub,Term_sub} and constructors {Case
            ,Cons_sum,Cons_usual,Id,Left,Right,Sum_constant,Sum_term_var,Term_app,Term_inl,Term_inr,Term_pair,Term_var}
    + Applied Processor:
        NaturalPI {shape = Mixed 2, restrict = Restrict, uargs = UArgs, urules = URules, selector = Just any strict-rules}
    + Details:
        We apply a polynomial interpretation of kind constructor-based(mixed(2)):
        The following argument positions are considered usable:
          uargs(Case) = {1,3},
          uargs(Cons_sum) = {3},
          uargs(Cons_usual) = {2,3},
          uargs(Frozen) = {2},
          uargs(Term_app) = {1,2},
          uargs(Term_inl) = {1},
          uargs(Term_inr) = {1},
          uargs(Term_pair) = {1,2}
        
        Following symbols are considered usable:
          {Concat,Frozen,Sum_sub,Term_sub}
        TcT has computed the following interpretation:
                  p(Case) = 1 + x1 + x3                                      
                p(Concat) = 2 + x1 + 2*x1*x2 + 2*x1^2                        
              p(Cons_sum) = x1 + x2 + x3                                     
            p(Cons_usual) = x2 + x3                                          
                p(Frozen) = 1 + 2*x1*x4 + 2*x1^2 + x2 + 2*x3*x4 + 2*x3^2 + x4
                    p(Id) = 1                                                
                  p(Left) = 0                                                
                 p(Right) = 0                                                
          p(Sum_constant) = 0                                                
               p(Sum_sub) = 0                                                
          p(Sum_term_var) = 0                                                
              p(Term_app) = x1 + x2                                          
              p(Term_inl) = 1 + x1                                           
              p(Term_inr) = x1                                               
             p(Term_pair) = x1 + x2                                          
              p(Term_sub) = 2*x1*x2 + 2*x1^2                                 
              p(Term_var) = 1                                                
        
        Following rules are strictly oriented:
         Frozen(m,Sum_constant(Left()),n,s) = 1 + 2*m*s + 2*m^2 + 2*n*s + 2*n^2 + s                      
                                            > 2*m*s + 2*m^2                                              
                                            = Term_sub(m,s)                                              
        
        Frozen(m,Sum_constant(Right()),n,s) = 1 + 2*m*s + 2*m^2 + 2*n*s + 2*n^2 + s                      
                                            > 2*n*s + 2*n^2                                              
                                            = Term_sub(n,s)                                              
        
                   Term_sub(Case(m,xi,n),s) = 2 + 4*m + 4*m*n + 2*m*s + 2*m^2 + 4*n + 2*n*s + 2*n^2 + 2*s
                                            > 1 + 2*m*s + 2*m^2 + 2*n*s + 2*n^2 + s                      
                                            = Frozen(m,Sum_sub(xi,s),n,s)                                
        
                    Term_sub(Term_inl(m),s) = 2 + 4*m + 2*m*s + 2*m^2 + 2*s                              
                                            > 1 + 2*m*s + 2*m^2                                          
                                            = Term_inl(Term_sub(m,s))                                    
        
        
        Following rules are (at-least) weakly oriented:
                     Concat(Cons_sum(xi,k,s),t) =  2 + k + 4*k*s + 2*k*t + 4*k*xi + 2*k^2 + s + 2*s*t + 4*s*xi + 2*s^2 + 2*t*xi + xi + 2*xi^2
                                                >= 2 + k + s + 2*s*t + 2*s^2 + xi                                                            
                                                =  Cons_sum(xi,k,Concat(s,t))                                                                
        
                    Concat(Cons_usual(x,m,s),t) =  2 + m + 4*m*s + 2*m*t + 2*m^2 + s + 2*s*t + 2*s^2                                         
                                                >= 2 + 2*m*t + 2*m^2 + s + 2*s*t + 2*s^2                                                     
                                                =  Cons_usual(x,Term_sub(m,t),Concat(s,t))                                                   
        
                                 Concat(Id(),s) =  5 + 2*s                                                                                   
                                                >= s                                                                                         
                                                =  s                                                                                         
        
                 Frozen(m,Sum_term_var(xi),n,s) =  1 + 2*m*s + 2*m^2 + 2*n*s + 2*n^2 + s                                                     
                                                >= 1 + 2*m*s + 2*m^2 + 2*n*s + 2*n^2                                                         
                                                =  Case(Term_sub(m,s),xi,Term_sub(n,s))                                                      
        
                  Sum_sub(xi,Cons_sum(psi,k,s)) =  0                                                                                         
                                                >= 0                                                                                         
                                                =  Sum_constant(k)                                                                           
        
                  Sum_sub(xi,Cons_sum(psi,k,s)) =  0                                                                                         
                                                >= 0                                                                                         
                                                =  Sum_sub(xi,s)                                                                             
        
                  Sum_sub(xi,Cons_usual(y,m,s)) =  0                                                                                         
                                                >= 0                                                                                         
                                                =  Sum_sub(xi,s)                                                                             
        
                               Sum_sub(xi,Id()) =  0                                                                                         
                                                >= 0                                                                                         
                                                =  Sum_term_var(xi)                                                                          
        
                      Term_sub(Term_app(m,n),s) =  4*m*n + 2*m*s + 2*m^2 + 2*n*s + 2*n^2                                                     
                                                >= 2*m*s + 2*m^2 + 2*n*s + 2*n^2                                                             
                                                =  Term_app(Term_sub(m,s),Term_sub(n,s))                                                     
        
                        Term_sub(Term_inr(m),s) =  2*m*s + 2*m^2                                                                             
                                                >= 2*m*s + 2*m^2                                                                             
                                                =  Term_inr(Term_sub(m,s))                                                                   
        
                     Term_sub(Term_pair(m,n),s) =  4*m*n + 2*m*s + 2*m^2 + 2*n*s + 2*n^2                                                     
                                                >= 2*m*s + 2*m^2 + 2*n*s + 2*n^2                                                             
                                                =  Term_pair(Term_sub(m,s),Term_sub(n,s))                                                    
        
         Term_sub(Term_var(x),Cons_sum(xi,k,s)) =  2 + 2*k + 2*s + 2*xi                                                                      
                                                >= 2 + 2*s                                                                                   
                                                =  Term_sub(Term_var(x),s)                                                                   
        
        Term_sub(Term_var(x),Cons_usual(y,m,s)) =  2 + 2*m + 2*s                                                                             
                                                >= m                                                                                         
                                                =  m                                                                                         
        
        Term_sub(Term_var(x),Cons_usual(y,m,s)) =  2 + 2*m + 2*s                                                                             
                                                >= 2 + 2*s                                                                                   
                                                =  Term_sub(Term_var(x),s)                                                                   
        
                     Term_sub(Term_var(x),Id()) =  4                                                                                         
                                                >= 1                                                                                         
                                                =  Term_var(x)                                                                               
        
* Step 3: NaturalPI WORST_CASE(?,O(n^2))
    + Considered Problem:
        - Strict TRS:
            Concat(Cons_sum(xi,k,s),t) -> Cons_sum(xi,k,Concat(s,t))
            Concat(Cons_usual(x,m,s),t) -> Cons_usual(x,Term_sub(m,t),Concat(s,t))
            Frozen(m,Sum_term_var(xi),n,s) -> Case(Term_sub(m,s),xi,Term_sub(n,s))
            Sum_sub(xi,Cons_sum(psi,k,s)) -> Sum_constant(k)
            Sum_sub(xi,Cons_sum(psi,k,s)) -> Sum_sub(xi,s)
            Sum_sub(xi,Cons_usual(y,m,s)) -> Sum_sub(xi,s)
            Sum_sub(xi,Id()) -> Sum_term_var(xi)
            Term_sub(Term_var(x),Cons_sum(xi,k,s)) -> Term_sub(Term_var(x),s)
            Term_sub(Term_var(x),Cons_usual(y,m,s)) -> Term_sub(Term_var(x),s)
        - Weak TRS:
            Concat(Id(),s) -> s
            Frozen(m,Sum_constant(Left()),n,s) -> Term_sub(m,s)
            Frozen(m,Sum_constant(Right()),n,s) -> Term_sub(n,s)
            Term_sub(Case(m,xi,n),s) -> Frozen(m,Sum_sub(xi,s),n,s)
            Term_sub(Term_app(m,n),s) -> Term_app(Term_sub(m,s),Term_sub(n,s))
            Term_sub(Term_inl(m),s) -> Term_inl(Term_sub(m,s))
            Term_sub(Term_inr(m),s) -> Term_inr(Term_sub(m,s))
            Term_sub(Term_pair(m,n),s) -> Term_pair(Term_sub(m,s),Term_sub(n,s))
            Term_sub(Term_var(x),Cons_usual(y,m,s)) -> m
            Term_sub(Term_var(x),Id()) -> Term_var(x)
        - Signature:
            {Concat/2,Frozen/4,Sum_sub/2,Term_sub/2} / {Case/3,Cons_sum/3,Cons_usual/3,Id/0,Left/0,Right/0
            ,Sum_constant/1,Sum_term_var/1,Term_app/2,Term_inl/1,Term_inr/1,Term_pair/2,Term_var/1}
        - Obligation:
            innermost runtime complexity wrt. defined symbols {Concat,Frozen,Sum_sub,Term_sub} and constructors {Case
            ,Cons_sum,Cons_usual,Id,Left,Right,Sum_constant,Sum_term_var,Term_app,Term_inl,Term_inr,Term_pair,Term_var}
    + Applied Processor:
        NaturalPI {shape = Mixed 2, restrict = Restrict, uargs = UArgs, urules = URules, selector = Just any strict-rules}
    + Details:
        We apply a polynomial interpretation of kind constructor-based(mixed(2)):
        The following argument positions are considered usable:
          uargs(Case) = {1,3},
          uargs(Cons_sum) = {3},
          uargs(Cons_usual) = {2,3},
          uargs(Frozen) = {2},
          uargs(Term_app) = {1,2},
          uargs(Term_inl) = {1},
          uargs(Term_inr) = {1},
          uargs(Term_pair) = {1,2}
        
        Following symbols are considered usable:
          {Concat,Frozen,Sum_sub,Term_sub}
        TcT has computed the following interpretation:
                  p(Case) = x1 + x3                     
                p(Concat) = 3*x1 + x1*x2 + x1^2 + 2*x2^2
              p(Cons_sum) = 1 + x3                      
            p(Cons_usual) = x2 + x3                     
                p(Frozen) = x1*x4 + 2*x2 + x2*x3 + x3*x4
                    p(Id) = 1                           
                  p(Left) = 1                           
                 p(Right) = 0                           
          p(Sum_constant) = 0                           
               p(Sum_sub) = 0                           
          p(Sum_term_var) = 0                           
              p(Term_app) = x1 + x2                     
              p(Term_inl) = x1                          
              p(Term_inr) = x1                          
             p(Term_pair) = x1 + x2                     
              p(Term_sub) = x1*x2                       
              p(Term_var) = 1                           
        
        Following rules are strictly oriented:
                    Concat(Cons_sum(xi,k,s),t) = 4 + 5*s + s*t + s^2 + t + 2*t^2
                                               > 1 + 3*s + s*t + s^2 + 2*t^2    
                                               = Cons_sum(xi,k,Concat(s,t))     
        
        Term_sub(Term_var(x),Cons_sum(xi,k,s)) = 1 + s                          
                                               > s                              
                                               = Term_sub(Term_var(x),s)        
        
        
        Following rules are (at-least) weakly oriented:
                    Concat(Cons_usual(x,m,s),t) =  3*m + 2*m*s + m*t + m^2 + 3*s + s*t + s^2 + 2*t^2
                                                >= m*t + 3*s + s*t + s^2 + 2*t^2                    
                                                =  Cons_usual(x,Term_sub(m,t),Concat(s,t))          
        
                                 Concat(Id(),s) =  4 + s + 2*s^2                                    
                                                >= s                                                
                                                =  s                                                
        
             Frozen(m,Sum_constant(Left()),n,s) =  m*s + n*s                                        
                                                >= m*s                                              
                                                =  Term_sub(m,s)                                    
        
            Frozen(m,Sum_constant(Right()),n,s) =  m*s + n*s                                        
                                                >= n*s                                              
                                                =  Term_sub(n,s)                                    
        
                 Frozen(m,Sum_term_var(xi),n,s) =  m*s + n*s                                        
                                                >= m*s + n*s                                        
                                                =  Case(Term_sub(m,s),xi,Term_sub(n,s))             
        
                  Sum_sub(xi,Cons_sum(psi,k,s)) =  0                                                
                                                >= 0                                                
                                                =  Sum_constant(k)                                  
        
                  Sum_sub(xi,Cons_sum(psi,k,s)) =  0                                                
                                                >= 0                                                
                                                =  Sum_sub(xi,s)                                    
        
                  Sum_sub(xi,Cons_usual(y,m,s)) =  0                                                
                                                >= 0                                                
                                                =  Sum_sub(xi,s)                                    
        
                               Sum_sub(xi,Id()) =  0                                                
                                                >= 0                                                
                                                =  Sum_term_var(xi)                                 
        
                       Term_sub(Case(m,xi,n),s) =  m*s + n*s                                        
                                                >= m*s + n*s                                        
                                                =  Frozen(m,Sum_sub(xi,s),n,s)                      
        
                      Term_sub(Term_app(m,n),s) =  m*s + n*s                                        
                                                >= m*s + n*s                                        
                                                =  Term_app(Term_sub(m,s),Term_sub(n,s))            
        
                        Term_sub(Term_inl(m),s) =  m*s                                              
                                                >= m*s                                              
                                                =  Term_inl(Term_sub(m,s))                          
        
                        Term_sub(Term_inr(m),s) =  m*s                                              
                                                >= m*s                                              
                                                =  Term_inr(Term_sub(m,s))                          
        
                     Term_sub(Term_pair(m,n),s) =  m*s + n*s                                        
                                                >= m*s + n*s                                        
                                                =  Term_pair(Term_sub(m,s),Term_sub(n,s))           
        
        Term_sub(Term_var(x),Cons_usual(y,m,s)) =  m + s                                            
                                                >= m                                                
                                                =  m                                                
        
        Term_sub(Term_var(x),Cons_usual(y,m,s)) =  m + s                                            
                                                >= s                                                
                                                =  Term_sub(Term_var(x),s)                          
        
                     Term_sub(Term_var(x),Id()) =  1                                                
                                                >= 1                                                
                                                =  Term_var(x)                                      
        
* Step 4: NaturalPI WORST_CASE(?,O(n^2))
    + Considered Problem:
        - Strict TRS:
            Concat(Cons_usual(x,m,s),t) -> Cons_usual(x,Term_sub(m,t),Concat(s,t))
            Frozen(m,Sum_term_var(xi),n,s) -> Case(Term_sub(m,s),xi,Term_sub(n,s))
            Sum_sub(xi,Cons_sum(psi,k,s)) -> Sum_constant(k)
            Sum_sub(xi,Cons_sum(psi,k,s)) -> Sum_sub(xi,s)
            Sum_sub(xi,Cons_usual(y,m,s)) -> Sum_sub(xi,s)
            Sum_sub(xi,Id()) -> Sum_term_var(xi)
            Term_sub(Term_var(x),Cons_usual(y,m,s)) -> Term_sub(Term_var(x),s)
        - Weak TRS:
            Concat(Cons_sum(xi,k,s),t) -> Cons_sum(xi,k,Concat(s,t))
            Concat(Id(),s) -> s
            Frozen(m,Sum_constant(Left()),n,s) -> Term_sub(m,s)
            Frozen(m,Sum_constant(Right()),n,s) -> Term_sub(n,s)
            Term_sub(Case(m,xi,n),s) -> Frozen(m,Sum_sub(xi,s),n,s)
            Term_sub(Term_app(m,n),s) -> Term_app(Term_sub(m,s),Term_sub(n,s))
            Term_sub(Term_inl(m),s) -> Term_inl(Term_sub(m,s))
            Term_sub(Term_inr(m),s) -> Term_inr(Term_sub(m,s))
            Term_sub(Term_pair(m,n),s) -> Term_pair(Term_sub(m,s),Term_sub(n,s))
            Term_sub(Term_var(x),Cons_sum(xi,k,s)) -> Term_sub(Term_var(x),s)
            Term_sub(Term_var(x),Cons_usual(y,m,s)) -> m
            Term_sub(Term_var(x),Id()) -> Term_var(x)
        - Signature:
            {Concat/2,Frozen/4,Sum_sub/2,Term_sub/2} / {Case/3,Cons_sum/3,Cons_usual/3,Id/0,Left/0,Right/0
            ,Sum_constant/1,Sum_term_var/1,Term_app/2,Term_inl/1,Term_inr/1,Term_pair/2,Term_var/1}
        - Obligation:
            innermost runtime complexity wrt. defined symbols {Concat,Frozen,Sum_sub,Term_sub} and constructors {Case
            ,Cons_sum,Cons_usual,Id,Left,Right,Sum_constant,Sum_term_var,Term_app,Term_inl,Term_inr,Term_pair,Term_var}
    + Applied Processor:
        NaturalPI {shape = Mixed 2, restrict = Restrict, uargs = UArgs, urules = URules, selector = Just any strict-rules}
    + Details:
        We apply a polynomial interpretation of kind constructor-based(mixed(2)):
        The following argument positions are considered usable:
          uargs(Case) = {1,3},
          uargs(Cons_sum) = {3},
          uargs(Cons_usual) = {2,3},
          uargs(Frozen) = {2},
          uargs(Term_app) = {1,2},
          uargs(Term_inl) = {1},
          uargs(Term_inr) = {1},
          uargs(Term_pair) = {1,2}
        
        Following symbols are considered usable:
          {Concat,Frozen,Sum_sub,Term_sub}
        TcT has computed the following interpretation:
                  p(Case) = 1 + x1 + x3                                       
                p(Concat) = 1 + x1 + 3*x1*x2 + 3*x1^2 + 3*x2                  
              p(Cons_sum) = 1 + x3                                            
            p(Cons_usual) = x2 + x3                                           
                p(Frozen) = 1 + x1 + 2*x1*x4 + x1^2 + x2 + 2*x3*x4 + x3^2 + x4
                    p(Id) = 0                                                 
                  p(Left) = 0                                                 
                 p(Right) = 1                                                 
          p(Sum_constant) = 0                                                 
               p(Sum_sub) = x2                                                
          p(Sum_term_var) = 0                                                 
              p(Term_app) = x1 + x2                                           
              p(Term_inl) = 1 + x1                                            
              p(Term_inr) = x1                                                
             p(Term_pair) = x1 + x2                                           
              p(Term_sub) = 2*x1*x2 + x1^2                                    
              p(Term_var) = 1                                                 
        
        Following rules are strictly oriented:
        Sum_sub(xi,Cons_sum(psi,k,s)) = 1 + s          
                                      > 0              
                                      = Sum_constant(k)
        
        Sum_sub(xi,Cons_sum(psi,k,s)) = 1 + s          
                                      > s              
                                      = Sum_sub(xi,s)  
        
        
        Following rules are (at-least) weakly oriented:
                     Concat(Cons_sum(xi,k,s),t) =  5 + 7*s + 3*s*t + 3*s^2 + 6*t                          
                                                >= 2 + s + 3*s*t + 3*s^2 + 3*t                            
                                                =  Cons_sum(xi,k,Concat(s,t))                             
        
                    Concat(Cons_usual(x,m,s),t) =  1 + m + 6*m*s + 3*m*t + 3*m^2 + s + 3*s*t + 3*s^2 + 3*t
                                                >= 1 + 2*m*t + m^2 + s + 3*s*t + 3*s^2 + 3*t              
                                                =  Cons_usual(x,Term_sub(m,t),Concat(s,t))                
        
                                 Concat(Id(),s) =  1 + 3*s                                                
                                                >= s                                                      
                                                =  s                                                      
        
             Frozen(m,Sum_constant(Left()),n,s) =  1 + m + 2*m*s + m^2 + 2*n*s + n^2 + s                  
                                                >= 2*m*s + m^2                                            
                                                =  Term_sub(m,s)                                          
        
            Frozen(m,Sum_constant(Right()),n,s) =  1 + m + 2*m*s + m^2 + 2*n*s + n^2 + s                  
                                                >= 2*n*s + n^2                                            
                                                =  Term_sub(n,s)                                          
        
                 Frozen(m,Sum_term_var(xi),n,s) =  1 + m + 2*m*s + m^2 + 2*n*s + n^2 + s                  
                                                >= 1 + 2*m*s + m^2 + 2*n*s + n^2                          
                                                =  Case(Term_sub(m,s),xi,Term_sub(n,s))                   
        
                  Sum_sub(xi,Cons_usual(y,m,s)) =  m + s                                                  
                                                >= s                                                      
                                                =  Sum_sub(xi,s)                                          
        
                               Sum_sub(xi,Id()) =  0                                                      
                                                >= 0                                                      
                                                =  Sum_term_var(xi)                                       
        
                       Term_sub(Case(m,xi,n),s) =  1 + 2*m + 2*m*n + 2*m*s + m^2 + 2*n + 2*n*s + n^2 + 2*s
                                                >= 1 + m + 2*m*s + m^2 + 2*n*s + n^2 + 2*s                
                                                =  Frozen(m,Sum_sub(xi,s),n,s)                            
        
                      Term_sub(Term_app(m,n),s) =  2*m*n + 2*m*s + m^2 + 2*n*s + n^2                      
                                                >= 2*m*s + m^2 + 2*n*s + n^2                              
                                                =  Term_app(Term_sub(m,s),Term_sub(n,s))                  
        
                        Term_sub(Term_inl(m),s) =  1 + 2*m + 2*m*s + m^2 + 2*s                            
                                                >= 1 + 2*m*s + m^2                                        
                                                =  Term_inl(Term_sub(m,s))                                
        
                        Term_sub(Term_inr(m),s) =  2*m*s + m^2                                            
                                                >= 2*m*s + m^2                                            
                                                =  Term_inr(Term_sub(m,s))                                
        
                     Term_sub(Term_pair(m,n),s) =  2*m*n + 2*m*s + m^2 + 2*n*s + n^2                      
                                                >= 2*m*s + m^2 + 2*n*s + n^2                              
                                                =  Term_pair(Term_sub(m,s),Term_sub(n,s))                 
        
         Term_sub(Term_var(x),Cons_sum(xi,k,s)) =  3 + 2*s                                                
                                                >= 1 + 2*s                                                
                                                =  Term_sub(Term_var(x),s)                                
        
        Term_sub(Term_var(x),Cons_usual(y,m,s)) =  1 + 2*m + 2*s                                          
                                                >= m                                                      
                                                =  m                                                      
        
        Term_sub(Term_var(x),Cons_usual(y,m,s)) =  1 + 2*m + 2*s                                          
                                                >= 1 + 2*s                                                
                                                =  Term_sub(Term_var(x),s)                                
        
                     Term_sub(Term_var(x),Id()) =  1                                                      
                                                >= 1                                                      
                                                =  Term_var(x)                                            
        
* Step 5: NaturalPI WORST_CASE(?,O(n^2))
    + Considered Problem:
        - Strict TRS:
            Concat(Cons_usual(x,m,s),t) -> Cons_usual(x,Term_sub(m,t),Concat(s,t))
            Frozen(m,Sum_term_var(xi),n,s) -> Case(Term_sub(m,s),xi,Term_sub(n,s))
            Sum_sub(xi,Cons_usual(y,m,s)) -> Sum_sub(xi,s)
            Sum_sub(xi,Id()) -> Sum_term_var(xi)
            Term_sub(Term_var(x),Cons_usual(y,m,s)) -> Term_sub(Term_var(x),s)
        - Weak TRS:
            Concat(Cons_sum(xi,k,s),t) -> Cons_sum(xi,k,Concat(s,t))
            Concat(Id(),s) -> s
            Frozen(m,Sum_constant(Left()),n,s) -> Term_sub(m,s)
            Frozen(m,Sum_constant(Right()),n,s) -> Term_sub(n,s)
            Sum_sub(xi,Cons_sum(psi,k,s)) -> Sum_constant(k)
            Sum_sub(xi,Cons_sum(psi,k,s)) -> Sum_sub(xi,s)
            Term_sub(Case(m,xi,n),s) -> Frozen(m,Sum_sub(xi,s),n,s)
            Term_sub(Term_app(m,n),s) -> Term_app(Term_sub(m,s),Term_sub(n,s))
            Term_sub(Term_inl(m),s) -> Term_inl(Term_sub(m,s))
            Term_sub(Term_inr(m),s) -> Term_inr(Term_sub(m,s))
            Term_sub(Term_pair(m,n),s) -> Term_pair(Term_sub(m,s),Term_sub(n,s))
            Term_sub(Term_var(x),Cons_sum(xi,k,s)) -> Term_sub(Term_var(x),s)
            Term_sub(Term_var(x),Cons_usual(y,m,s)) -> m
            Term_sub(Term_var(x),Id()) -> Term_var(x)
        - Signature:
            {Concat/2,Frozen/4,Sum_sub/2,Term_sub/2} / {Case/3,Cons_sum/3,Cons_usual/3,Id/0,Left/0,Right/0
            ,Sum_constant/1,Sum_term_var/1,Term_app/2,Term_inl/1,Term_inr/1,Term_pair/2,Term_var/1}
        - Obligation:
            innermost runtime complexity wrt. defined symbols {Concat,Frozen,Sum_sub,Term_sub} and constructors {Case
            ,Cons_sum,Cons_usual,Id,Left,Right,Sum_constant,Sum_term_var,Term_app,Term_inl,Term_inr,Term_pair,Term_var}
    + Applied Processor:
        NaturalPI {shape = Mixed 2, restrict = Restrict, uargs = UArgs, urules = URules, selector = Just any strict-rules}
    + Details:
        We apply a polynomial interpretation of kind constructor-based(mixed(2)):
        The following argument positions are considered usable:
          uargs(Case) = {1,3},
          uargs(Cons_sum) = {3},
          uargs(Cons_usual) = {2,3},
          uargs(Frozen) = {2},
          uargs(Term_app) = {1,2},
          uargs(Term_inl) = {1},
          uargs(Term_inr) = {1},
          uargs(Term_pair) = {1,2}
        
        Following symbols are considered usable:
          {Concat,Frozen,Sum_sub,Term_sub}
        TcT has computed the following interpretation:
                  p(Case) = x1 + x3                         
                p(Concat) = 3 + 3*x1 + 2*x1*x2 + 3*x2^2     
              p(Cons_sum) = x2 + x3                         
            p(Cons_usual) = 1 + x1 + x2 + x3                
                p(Frozen) = 2*x1*x4 + x2 + 2*x2*x3 + 2*x3*x4
                    p(Id) = 1                               
                  p(Left) = 1                               
                 p(Right) = 0                               
          p(Sum_constant) = 0                               
               p(Sum_sub) = 0                               
          p(Sum_term_var) = 0                               
              p(Term_app) = x1 + x2                         
              p(Term_inl) = x1                              
              p(Term_inr) = x1                              
             p(Term_pair) = x1 + x2                         
              p(Term_sub) = 2*x1*x2                         
              p(Term_var) = 1                               
        
        Following rules are strictly oriented:
                    Concat(Cons_usual(x,m,s),t) = 6 + 3*m + 2*m*t + 3*s + 2*s*t + 2*t + 2*t*x + 3*t^2 + 3*x
                                                > 4 + 2*m*t + 3*s + 2*s*t + 3*t^2 + x                      
                                                = Cons_usual(x,Term_sub(m,t),Concat(s,t))                  
        
        Term_sub(Term_var(x),Cons_usual(y,m,s)) = 2 + 2*m + 2*s + 2*y                                      
                                                > 2*s                                                      
                                                = Term_sub(Term_var(x),s)                                  
        
        
        Following rules are (at-least) weakly oriented:
                     Concat(Cons_sum(xi,k,s),t) =  3 + 3*k + 2*k*t + 3*s + 2*s*t + 3*t^2 
                                                >= 3 + k + 3*s + 2*s*t + 3*t^2           
                                                =  Cons_sum(xi,k,Concat(s,t))            
        
                                 Concat(Id(),s) =  6 + 2*s + 3*s^2                       
                                                >= s                                     
                                                =  s                                     
        
             Frozen(m,Sum_constant(Left()),n,s) =  2*m*s + 2*n*s                         
                                                >= 2*m*s                                 
                                                =  Term_sub(m,s)                         
        
            Frozen(m,Sum_constant(Right()),n,s) =  2*m*s + 2*n*s                         
                                                >= 2*n*s                                 
                                                =  Term_sub(n,s)                         
        
                 Frozen(m,Sum_term_var(xi),n,s) =  2*m*s + 2*n*s                         
                                                >= 2*m*s + 2*n*s                         
                                                =  Case(Term_sub(m,s),xi,Term_sub(n,s))  
        
                  Sum_sub(xi,Cons_sum(psi,k,s)) =  0                                     
                                                >= 0                                     
                                                =  Sum_constant(k)                       
        
                  Sum_sub(xi,Cons_sum(psi,k,s)) =  0                                     
                                                >= 0                                     
                                                =  Sum_sub(xi,s)                         
        
                  Sum_sub(xi,Cons_usual(y,m,s)) =  0                                     
                                                >= 0                                     
                                                =  Sum_sub(xi,s)                         
        
                               Sum_sub(xi,Id()) =  0                                     
                                                >= 0                                     
                                                =  Sum_term_var(xi)                      
        
                       Term_sub(Case(m,xi,n),s) =  2*m*s + 2*n*s                         
                                                >= 2*m*s + 2*n*s                         
                                                =  Frozen(m,Sum_sub(xi,s),n,s)           
        
                      Term_sub(Term_app(m,n),s) =  2*m*s + 2*n*s                         
                                                >= 2*m*s + 2*n*s                         
                                                =  Term_app(Term_sub(m,s),Term_sub(n,s)) 
        
                        Term_sub(Term_inl(m),s) =  2*m*s                                 
                                                >= 2*m*s                                 
                                                =  Term_inl(Term_sub(m,s))               
        
                        Term_sub(Term_inr(m),s) =  2*m*s                                 
                                                >= 2*m*s                                 
                                                =  Term_inr(Term_sub(m,s))               
        
                     Term_sub(Term_pair(m,n),s) =  2*m*s + 2*n*s                         
                                                >= 2*m*s + 2*n*s                         
                                                =  Term_pair(Term_sub(m,s),Term_sub(n,s))
        
         Term_sub(Term_var(x),Cons_sum(xi,k,s)) =  2*k + 2*s                             
                                                >= 2*s                                   
                                                =  Term_sub(Term_var(x),s)               
        
        Term_sub(Term_var(x),Cons_usual(y,m,s)) =  2 + 2*m + 2*s + 2*y                   
                                                >= m                                     
                                                =  m                                     
        
                     Term_sub(Term_var(x),Id()) =  2                                     
                                                >= 1                                     
                                                =  Term_var(x)                           
        
* Step 6: NaturalPI WORST_CASE(?,O(n^2))
    + Considered Problem:
        - Strict TRS:
            Frozen(m,Sum_term_var(xi),n,s) -> Case(Term_sub(m,s),xi,Term_sub(n,s))
            Sum_sub(xi,Cons_usual(y,m,s)) -> Sum_sub(xi,s)
            Sum_sub(xi,Id()) -> Sum_term_var(xi)
        - Weak TRS:
            Concat(Cons_sum(xi,k,s),t) -> Cons_sum(xi,k,Concat(s,t))
            Concat(Cons_usual(x,m,s),t) -> Cons_usual(x,Term_sub(m,t),Concat(s,t))
            Concat(Id(),s) -> s
            Frozen(m,Sum_constant(Left()),n,s) -> Term_sub(m,s)
            Frozen(m,Sum_constant(Right()),n,s) -> Term_sub(n,s)
            Sum_sub(xi,Cons_sum(psi,k,s)) -> Sum_constant(k)
            Sum_sub(xi,Cons_sum(psi,k,s)) -> Sum_sub(xi,s)
            Term_sub(Case(m,xi,n),s) -> Frozen(m,Sum_sub(xi,s),n,s)
            Term_sub(Term_app(m,n),s) -> Term_app(Term_sub(m,s),Term_sub(n,s))
            Term_sub(Term_inl(m),s) -> Term_inl(Term_sub(m,s))
            Term_sub(Term_inr(m),s) -> Term_inr(Term_sub(m,s))
            Term_sub(Term_pair(m,n),s) -> Term_pair(Term_sub(m,s),Term_sub(n,s))
            Term_sub(Term_var(x),Cons_sum(xi,k,s)) -> Term_sub(Term_var(x),s)
            Term_sub(Term_var(x),Cons_usual(y,m,s)) -> m
            Term_sub(Term_var(x),Cons_usual(y,m,s)) -> Term_sub(Term_var(x),s)
            Term_sub(Term_var(x),Id()) -> Term_var(x)
        - Signature:
            {Concat/2,Frozen/4,Sum_sub/2,Term_sub/2} / {Case/3,Cons_sum/3,Cons_usual/3,Id/0,Left/0,Right/0
            ,Sum_constant/1,Sum_term_var/1,Term_app/2,Term_inl/1,Term_inr/1,Term_pair/2,Term_var/1}
        - Obligation:
            innermost runtime complexity wrt. defined symbols {Concat,Frozen,Sum_sub,Term_sub} and constructors {Case
            ,Cons_sum,Cons_usual,Id,Left,Right,Sum_constant,Sum_term_var,Term_app,Term_inl,Term_inr,Term_pair,Term_var}
    + Applied Processor:
        NaturalPI {shape = Mixed 2, restrict = Restrict, uargs = UArgs, urules = URules, selector = Just any strict-rules}
    + Details:
        We apply a polynomial interpretation of kind constructor-based(mixed(2)):
        The following argument positions are considered usable:
          uargs(Case) = {1,3},
          uargs(Cons_sum) = {3},
          uargs(Cons_usual) = {2,3},
          uargs(Frozen) = {2},
          uargs(Term_app) = {1,2},
          uargs(Term_inl) = {1},
          uargs(Term_inr) = {1},
          uargs(Term_pair) = {1,2}
        
        Following symbols are considered usable:
          {Concat,Frozen,Sum_sub,Term_sub}
        TcT has computed the following interpretation:
                  p(Case) = 1 + x1 + x2 + x3                                                 
                p(Concat) = 2 + 2*x1 + 3*x1*x2 + 2*x1^2                                      
              p(Cons_sum) = 1 + x3                                                           
            p(Cons_usual) = x2 + x3                                                          
                p(Frozen) = 3 + 2*x1 + 3*x1*x4 + 2*x1^2 + x2 + 3*x3 + 3*x3*x4 + 2*x3^2 + 2*x4
                    p(Id) = 1                                                                
                  p(Left) = 1                                                                
                 p(Right) = 1                                                                
          p(Sum_constant) = 0                                                                
               p(Sum_sub) = 2*x1 + x2                                                        
          p(Sum_term_var) = 1 + x1                                                           
              p(Term_app) = x1 + x2                                                          
              p(Term_inl) = x1                                                               
              p(Term_inr) = x1                                                               
             p(Term_pair) = x1 + x2                                                          
              p(Term_sub) = x1 + 3*x1*x2 + 2*x1^2                                            
              p(Term_var) = 1                                                                
        
        Following rules are strictly oriented:
        Frozen(m,Sum_term_var(xi),n,s) = 4 + 2*m + 3*m*s + 2*m^2 + 3*n + 3*n*s + 2*n^2 + 2*s + xi
                                       > 1 + m + 3*m*s + 2*m^2 + n + 3*n*s + 2*n^2 + xi          
                                       = Case(Term_sub(m,s),xi,Term_sub(n,s))                    
        
        
        Following rules are (at-least) weakly oriented:
                     Concat(Cons_sum(xi,k,s),t) =  6 + 6*s + 3*s*t + 2*s^2 + 3*t                                                                         
                                                >= 3 + 2*s + 3*s*t + 2*s^2                                                                               
                                                =  Cons_sum(xi,k,Concat(s,t))                                                                            
        
                    Concat(Cons_usual(x,m,s),t) =  2 + 2*m + 4*m*s + 3*m*t + 2*m^2 + 2*s + 3*s*t + 2*s^2                                                 
                                                >= 2 + m + 3*m*t + 2*m^2 + 2*s + 3*s*t + 2*s^2                                                           
                                                =  Cons_usual(x,Term_sub(m,t),Concat(s,t))                                                               
        
                                 Concat(Id(),s) =  6 + 3*s                                                                                               
                                                >= s                                                                                                     
                                                =  s                                                                                                     
        
             Frozen(m,Sum_constant(Left()),n,s) =  3 + 2*m + 3*m*s + 2*m^2 + 3*n + 3*n*s + 2*n^2 + 2*s                                                   
                                                >= m + 3*m*s + 2*m^2                                                                                     
                                                =  Term_sub(m,s)                                                                                         
        
            Frozen(m,Sum_constant(Right()),n,s) =  3 + 2*m + 3*m*s + 2*m^2 + 3*n + 3*n*s + 2*n^2 + 2*s                                                   
                                                >= n + 3*n*s + 2*n^2                                                                                     
                                                =  Term_sub(n,s)                                                                                         
        
                  Sum_sub(xi,Cons_sum(psi,k,s)) =  1 + s + 2*xi                                                                                          
                                                >= 0                                                                                                     
                                                =  Sum_constant(k)                                                                                       
        
                  Sum_sub(xi,Cons_sum(psi,k,s)) =  1 + s + 2*xi                                                                                          
                                                >= s + 2*xi                                                                                              
                                                =  Sum_sub(xi,s)                                                                                         
        
                  Sum_sub(xi,Cons_usual(y,m,s)) =  m + s + 2*xi                                                                                          
                                                >= s + 2*xi                                                                                              
                                                =  Sum_sub(xi,s)                                                                                         
        
                               Sum_sub(xi,Id()) =  1 + 2*xi                                                                                              
                                                >= 1 + xi                                                                                                
                                                =  Sum_term_var(xi)                                                                                      
        
                       Term_sub(Case(m,xi,n),s) =  3 + 5*m + 4*m*n + 3*m*s + 4*m*xi + 2*m^2 + 5*n + 3*n*s + 4*n*xi + 2*n^2 + 3*s + 3*s*xi + 5*xi + 2*xi^2
                                                >= 3 + 2*m + 3*m*s + 2*m^2 + 3*n + 3*n*s + 2*n^2 + 3*s + 2*xi                                            
                                                =  Frozen(m,Sum_sub(xi,s),n,s)                                                                           
        
                      Term_sub(Term_app(m,n),s) =  m + 4*m*n + 3*m*s + 2*m^2 + n + 3*n*s + 2*n^2                                                         
                                                >= m + 3*m*s + 2*m^2 + n + 3*n*s + 2*n^2                                                                 
                                                =  Term_app(Term_sub(m,s),Term_sub(n,s))                                                                 
        
                        Term_sub(Term_inl(m),s) =  m + 3*m*s + 2*m^2                                                                                     
                                                >= m + 3*m*s + 2*m^2                                                                                     
                                                =  Term_inl(Term_sub(m,s))                                                                               
        
                        Term_sub(Term_inr(m),s) =  m + 3*m*s + 2*m^2                                                                                     
                                                >= m + 3*m*s + 2*m^2                                                                                     
                                                =  Term_inr(Term_sub(m,s))                                                                               
        
                     Term_sub(Term_pair(m,n),s) =  m + 4*m*n + 3*m*s + 2*m^2 + n + 3*n*s + 2*n^2                                                         
                                                >= m + 3*m*s + 2*m^2 + n + 3*n*s + 2*n^2                                                                 
                                                =  Term_pair(Term_sub(m,s),Term_sub(n,s))                                                                
        
         Term_sub(Term_var(x),Cons_sum(xi,k,s)) =  6 + 3*s                                                                                               
                                                >= 3 + 3*s                                                                                               
                                                =  Term_sub(Term_var(x),s)                                                                               
        
        Term_sub(Term_var(x),Cons_usual(y,m,s)) =  3 + 3*m + 3*s                                                                                         
                                                >= m                                                                                                     
                                                =  m                                                                                                     
        
        Term_sub(Term_var(x),Cons_usual(y,m,s)) =  3 + 3*m + 3*s                                                                                         
                                                >= 3 + 3*s                                                                                               
                                                =  Term_sub(Term_var(x),s)                                                                               
        
                     Term_sub(Term_var(x),Id()) =  6                                                                                                     
                                                >= 1                                                                                                     
                                                =  Term_var(x)                                                                                           
        
* Step 7: NaturalPI WORST_CASE(?,O(n^2))
    + Considered Problem:
        - Strict TRS:
            Sum_sub(xi,Cons_usual(y,m,s)) -> Sum_sub(xi,s)
            Sum_sub(xi,Id()) -> Sum_term_var(xi)
        - Weak TRS:
            Concat(Cons_sum(xi,k,s),t) -> Cons_sum(xi,k,Concat(s,t))
            Concat(Cons_usual(x,m,s),t) -> Cons_usual(x,Term_sub(m,t),Concat(s,t))
            Concat(Id(),s) -> s
            Frozen(m,Sum_constant(Left()),n,s) -> Term_sub(m,s)
            Frozen(m,Sum_constant(Right()),n,s) -> Term_sub(n,s)
            Frozen(m,Sum_term_var(xi),n,s) -> Case(Term_sub(m,s),xi,Term_sub(n,s))
            Sum_sub(xi,Cons_sum(psi,k,s)) -> Sum_constant(k)
            Sum_sub(xi,Cons_sum(psi,k,s)) -> Sum_sub(xi,s)
            Term_sub(Case(m,xi,n),s) -> Frozen(m,Sum_sub(xi,s),n,s)
            Term_sub(Term_app(m,n),s) -> Term_app(Term_sub(m,s),Term_sub(n,s))
            Term_sub(Term_inl(m),s) -> Term_inl(Term_sub(m,s))
            Term_sub(Term_inr(m),s) -> Term_inr(Term_sub(m,s))
            Term_sub(Term_pair(m,n),s) -> Term_pair(Term_sub(m,s),Term_sub(n,s))
            Term_sub(Term_var(x),Cons_sum(xi,k,s)) -> Term_sub(Term_var(x),s)
            Term_sub(Term_var(x),Cons_usual(y,m,s)) -> m
            Term_sub(Term_var(x),Cons_usual(y,m,s)) -> Term_sub(Term_var(x),s)
            Term_sub(Term_var(x),Id()) -> Term_var(x)
        - Signature:
            {Concat/2,Frozen/4,Sum_sub/2,Term_sub/2} / {Case/3,Cons_sum/3,Cons_usual/3,Id/0,Left/0,Right/0
            ,Sum_constant/1,Sum_term_var/1,Term_app/2,Term_inl/1,Term_inr/1,Term_pair/2,Term_var/1}
        - Obligation:
            innermost runtime complexity wrt. defined symbols {Concat,Frozen,Sum_sub,Term_sub} and constructors {Case
            ,Cons_sum,Cons_usual,Id,Left,Right,Sum_constant,Sum_term_var,Term_app,Term_inl,Term_inr,Term_pair,Term_var}
    + Applied Processor:
        NaturalPI {shape = Mixed 2, restrict = Restrict, uargs = UArgs, urules = URules, selector = Just any strict-rules}
    + Details:
        We apply a polynomial interpretation of kind constructor-based(mixed(2)):
        The following argument positions are considered usable:
          uargs(Case) = {1,3},
          uargs(Cons_sum) = {3},
          uargs(Cons_usual) = {2,3},
          uargs(Frozen) = {2},
          uargs(Term_app) = {1,2},
          uargs(Term_inl) = {1},
          uargs(Term_inr) = {1},
          uargs(Term_pair) = {1,2}
        
        Following symbols are considered usable:
          {Concat,Frozen,Sum_sub,Term_sub}
        TcT has computed the following interpretation:
                  p(Case) = 1 + x1 + x3                             
                p(Concat) = 1 + 2*x1 + 2*x1*x2 + 2*x1^2 + x2 + x2^2 
              p(Cons_sum) = x3                                      
            p(Cons_usual) = x1 + x2 + x3                            
                p(Frozen) = 1 + 2*x1*x4 + x1^2 + x2 + 2*x3*x4 + x3^2
                    p(Id) = 1                                       
                  p(Left) = 1                                       
                 p(Right) = 0                                       
          p(Sum_constant) = 0                                       
               p(Sum_sub) = x2                                      
          p(Sum_term_var) = 0                                       
              p(Term_app) = x1 + x2                                 
              p(Term_inl) = x1                                      
              p(Term_inr) = x1                                      
             p(Term_pair) = x1 + x2                                 
              p(Term_sub) = 2*x1*x2 + x1^2                          
              p(Term_var) = 1                                       
        
        Following rules are strictly oriented:
        Sum_sub(xi,Id()) = 1               
                         > 0               
                         = Sum_term_var(xi)
        
        
        Following rules are (at-least) weakly oriented:
                     Concat(Cons_sum(xi,k,s),t) =  1 + 2*s + 2*s*t + 2*s^2 + t + t^2                                                                    
                                                >= 1 + 2*s + 2*s*t + 2*s^2 + t + t^2                                                                    
                                                =  Cons_sum(xi,k,Concat(s,t))                                                                           
        
                    Concat(Cons_usual(x,m,s),t) =  1 + 2*m + 4*m*s + 2*m*t + 4*m*x + 2*m^2 + 2*s + 2*s*t + 4*s*x + 2*s^2 + t + 2*t*x + t^2 + 2*x + 2*x^2
                                                >= 1 + 2*m*t + m^2 + 2*s + 2*s*t + 2*s^2 + t + t^2 + x                                                  
                                                =  Cons_usual(x,Term_sub(m,t),Concat(s,t))                                                              
        
                                 Concat(Id(),s) =  5 + 3*s + s^2                                                                                        
                                                >= s                                                                                                    
                                                =  s                                                                                                    
        
             Frozen(m,Sum_constant(Left()),n,s) =  1 + 2*m*s + m^2 + 2*n*s + n^2                                                                        
                                                >= 2*m*s + m^2                                                                                          
                                                =  Term_sub(m,s)                                                                                        
        
            Frozen(m,Sum_constant(Right()),n,s) =  1 + 2*m*s + m^2 + 2*n*s + n^2                                                                        
                                                >= 2*n*s + n^2                                                                                          
                                                =  Term_sub(n,s)                                                                                        
        
                 Frozen(m,Sum_term_var(xi),n,s) =  1 + 2*m*s + m^2 + 2*n*s + n^2                                                                        
                                                >= 1 + 2*m*s + m^2 + 2*n*s + n^2                                                                        
                                                =  Case(Term_sub(m,s),xi,Term_sub(n,s))                                                                 
        
                  Sum_sub(xi,Cons_sum(psi,k,s)) =  s                                                                                                    
                                                >= 0                                                                                                    
                                                =  Sum_constant(k)                                                                                      
        
                  Sum_sub(xi,Cons_sum(psi,k,s)) =  s                                                                                                    
                                                >= s                                                                                                    
                                                =  Sum_sub(xi,s)                                                                                        
        
                  Sum_sub(xi,Cons_usual(y,m,s)) =  m + s + y                                                                                            
                                                >= s                                                                                                    
                                                =  Sum_sub(xi,s)                                                                                        
        
                       Term_sub(Case(m,xi,n),s) =  1 + 2*m + 2*m*n + 2*m*s + m^2 + 2*n + 2*n*s + n^2 + 2*s                                              
                                                >= 1 + 2*m*s + m^2 + 2*n*s + n^2 + s                                                                    
                                                =  Frozen(m,Sum_sub(xi,s),n,s)                                                                          
        
                      Term_sub(Term_app(m,n),s) =  2*m*n + 2*m*s + m^2 + 2*n*s + n^2                                                                    
                                                >= 2*m*s + m^2 + 2*n*s + n^2                                                                            
                                                =  Term_app(Term_sub(m,s),Term_sub(n,s))                                                                
        
                        Term_sub(Term_inl(m),s) =  2*m*s + m^2                                                                                          
                                                >= 2*m*s + m^2                                                                                          
                                                =  Term_inl(Term_sub(m,s))                                                                              
        
                        Term_sub(Term_inr(m),s) =  2*m*s + m^2                                                                                          
                                                >= 2*m*s + m^2                                                                                          
                                                =  Term_inr(Term_sub(m,s))                                                                              
        
                     Term_sub(Term_pair(m,n),s) =  2*m*n + 2*m*s + m^2 + 2*n*s + n^2                                                                    
                                                >= 2*m*s + m^2 + 2*n*s + n^2                                                                            
                                                =  Term_pair(Term_sub(m,s),Term_sub(n,s))                                                               
        
         Term_sub(Term_var(x),Cons_sum(xi,k,s)) =  1 + 2*s                                                                                              
                                                >= 1 + 2*s                                                                                              
                                                =  Term_sub(Term_var(x),s)                                                                              
        
        Term_sub(Term_var(x),Cons_usual(y,m,s)) =  1 + 2*m + 2*s + 2*y                                                                                  
                                                >= m                                                                                                    
                                                =  m                                                                                                    
        
        Term_sub(Term_var(x),Cons_usual(y,m,s)) =  1 + 2*m + 2*s + 2*y                                                                                  
                                                >= 1 + 2*s                                                                                              
                                                =  Term_sub(Term_var(x),s)                                                                              
        
                     Term_sub(Term_var(x),Id()) =  3                                                                                                    
                                                >= 1                                                                                                    
                                                =  Term_var(x)                                                                                          
        
* Step 8: NaturalPI WORST_CASE(?,O(n^2))
    + Considered Problem:
        - Strict TRS:
            Sum_sub(xi,Cons_usual(y,m,s)) -> Sum_sub(xi,s)
        - Weak TRS:
            Concat(Cons_sum(xi,k,s),t) -> Cons_sum(xi,k,Concat(s,t))
            Concat(Cons_usual(x,m,s),t) -> Cons_usual(x,Term_sub(m,t),Concat(s,t))
            Concat(Id(),s) -> s
            Frozen(m,Sum_constant(Left()),n,s) -> Term_sub(m,s)
            Frozen(m,Sum_constant(Right()),n,s) -> Term_sub(n,s)
            Frozen(m,Sum_term_var(xi),n,s) -> Case(Term_sub(m,s),xi,Term_sub(n,s))
            Sum_sub(xi,Cons_sum(psi,k,s)) -> Sum_constant(k)
            Sum_sub(xi,Cons_sum(psi,k,s)) -> Sum_sub(xi,s)
            Sum_sub(xi,Id()) -> Sum_term_var(xi)
            Term_sub(Case(m,xi,n),s) -> Frozen(m,Sum_sub(xi,s),n,s)
            Term_sub(Term_app(m,n),s) -> Term_app(Term_sub(m,s),Term_sub(n,s))
            Term_sub(Term_inl(m),s) -> Term_inl(Term_sub(m,s))
            Term_sub(Term_inr(m),s) -> Term_inr(Term_sub(m,s))
            Term_sub(Term_pair(m,n),s) -> Term_pair(Term_sub(m,s),Term_sub(n,s))
            Term_sub(Term_var(x),Cons_sum(xi,k,s)) -> Term_sub(Term_var(x),s)
            Term_sub(Term_var(x),Cons_usual(y,m,s)) -> m
            Term_sub(Term_var(x),Cons_usual(y,m,s)) -> Term_sub(Term_var(x),s)
            Term_sub(Term_var(x),Id()) -> Term_var(x)
        - Signature:
            {Concat/2,Frozen/4,Sum_sub/2,Term_sub/2} / {Case/3,Cons_sum/3,Cons_usual/3,Id/0,Left/0,Right/0
            ,Sum_constant/1,Sum_term_var/1,Term_app/2,Term_inl/1,Term_inr/1,Term_pair/2,Term_var/1}
        - Obligation:
            innermost runtime complexity wrt. defined symbols {Concat,Frozen,Sum_sub,Term_sub} and constructors {Case
            ,Cons_sum,Cons_usual,Id,Left,Right,Sum_constant,Sum_term_var,Term_app,Term_inl,Term_inr,Term_pair,Term_var}
    + Applied Processor:
        NaturalPI {shape = Mixed 2, restrict = Restrict, uargs = UArgs, urules = URules, selector = Just any strict-rules}
    + Details:
        We apply a polynomial interpretation of kind constructor-based(mixed(2)):
        The following argument positions are considered usable:
          uargs(Case) = {1,3},
          uargs(Cons_sum) = {3},
          uargs(Cons_usual) = {2,3},
          uargs(Frozen) = {2},
          uargs(Term_app) = {1,2},
          uargs(Term_inl) = {1},
          uargs(Term_inr) = {1},
          uargs(Term_pair) = {1,2}
        
        Following symbols are considered usable:
          {Concat,Frozen,Sum_sub,Term_sub}
        TcT has computed the following interpretation:
                  p(Case) = 1 + x1 + x3                                                     
                p(Concat) = x1 + 3*x1*x2 + 2*x1^2 + x2                                      
              p(Cons_sum) = x3                                                              
            p(Cons_usual) = 1 + x1 + x2 + x3                                                
                p(Frozen) = 3*x1 + 2*x1*x3 + 2*x1*x4 + 2*x1^2 + x2 + 2*x3 + 2*x3*x4 + 2*x3^2
                    p(Id) = 0                                                               
                  p(Left) = 1                                                               
                 p(Right) = 0                                                               
          p(Sum_constant) = 0                                                               
               p(Sum_sub) = 1 + 2*x2                                                        
          p(Sum_term_var) = 1                                                               
              p(Term_app) = x1 + x2                                                         
              p(Term_inl) = x1                                                              
              p(Term_inr) = x1                                                              
             p(Term_pair) = x1 + x2                                                         
              p(Term_sub) = 2*x1 + 2*x1*x2 + 2*x1^2                                         
              p(Term_var) = 1                                                               
        
        Following rules are strictly oriented:
        Sum_sub(xi,Cons_usual(y,m,s)) = 3 + 2*m + 2*s + 2*y
                                      > 1 + 2*s            
                                      = Sum_sub(xi,s)      
        
        
        Following rules are (at-least) weakly oriented:
                     Concat(Cons_sum(xi,k,s),t) =  s + 3*s*t + 2*s^2 + t                                                                            
                                                >= s + 3*s*t + 2*s^2 + t                                                                            
                                                =  Cons_sum(xi,k,Concat(s,t))                                                                       
        
                    Concat(Cons_usual(x,m,s),t) =  3 + 5*m + 4*m*s + 3*m*t + 4*m*x + 2*m^2 + 5*s + 3*s*t + 4*s*x + 2*s^2 + 4*t + 3*t*x + 5*x + 2*x^2
                                                >= 1 + 2*m + 2*m*t + 2*m^2 + s + 3*s*t + 2*s^2 + t + x                                              
                                                =  Cons_usual(x,Term_sub(m,t),Concat(s,t))                                                          
        
                                 Concat(Id(),s) =  s                                                                                                
                                                >= s                                                                                                
                                                =  s                                                                                                
        
             Frozen(m,Sum_constant(Left()),n,s) =  3*m + 2*m*n + 2*m*s + 2*m^2 + 2*n + 2*n*s + 2*n^2                                                
                                                >= 2*m + 2*m*s + 2*m^2                                                                              
                                                =  Term_sub(m,s)                                                                                    
        
            Frozen(m,Sum_constant(Right()),n,s) =  3*m + 2*m*n + 2*m*s + 2*m^2 + 2*n + 2*n*s + 2*n^2                                                
                                                >= 2*n + 2*n*s + 2*n^2                                                                              
                                                =  Term_sub(n,s)                                                                                    
        
                 Frozen(m,Sum_term_var(xi),n,s) =  1 + 3*m + 2*m*n + 2*m*s + 2*m^2 + 2*n + 2*n*s + 2*n^2                                            
                                                >= 1 + 2*m + 2*m*s + 2*m^2 + 2*n + 2*n*s + 2*n^2                                                    
                                                =  Case(Term_sub(m,s),xi,Term_sub(n,s))                                                             
        
                  Sum_sub(xi,Cons_sum(psi,k,s)) =  1 + 2*s                                                                                          
                                                >= 0                                                                                                
                                                =  Sum_constant(k)                                                                                  
        
                  Sum_sub(xi,Cons_sum(psi,k,s)) =  1 + 2*s                                                                                          
                                                >= 1 + 2*s                                                                                          
                                                =  Sum_sub(xi,s)                                                                                    
        
                               Sum_sub(xi,Id()) =  1                                                                                                
                                                >= 1                                                                                                
                                                =  Sum_term_var(xi)                                                                                 
        
                       Term_sub(Case(m,xi,n),s) =  4 + 6*m + 4*m*n + 2*m*s + 2*m^2 + 6*n + 2*n*s + 2*n^2 + 2*s                                      
                                                >= 1 + 3*m + 2*m*n + 2*m*s + 2*m^2 + 2*n + 2*n*s + 2*n^2 + 2*s                                      
                                                =  Frozen(m,Sum_sub(xi,s),n,s)                                                                      
        
                      Term_sub(Term_app(m,n),s) =  2*m + 4*m*n + 2*m*s + 2*m^2 + 2*n + 2*n*s + 2*n^2                                                
                                                >= 2*m + 2*m*s + 2*m^2 + 2*n + 2*n*s + 2*n^2                                                        
                                                =  Term_app(Term_sub(m,s),Term_sub(n,s))                                                            
        
                        Term_sub(Term_inl(m),s) =  2*m + 2*m*s + 2*m^2                                                                              
                                                >= 2*m + 2*m*s + 2*m^2                                                                              
                                                =  Term_inl(Term_sub(m,s))                                                                          
        
                        Term_sub(Term_inr(m),s) =  2*m + 2*m*s + 2*m^2                                                                              
                                                >= 2*m + 2*m*s + 2*m^2                                                                              
                                                =  Term_inr(Term_sub(m,s))                                                                          
        
                     Term_sub(Term_pair(m,n),s) =  2*m + 4*m*n + 2*m*s + 2*m^2 + 2*n + 2*n*s + 2*n^2                                                
                                                >= 2*m + 2*m*s + 2*m^2 + 2*n + 2*n*s + 2*n^2                                                        
                                                =  Term_pair(Term_sub(m,s),Term_sub(n,s))                                                           
        
         Term_sub(Term_var(x),Cons_sum(xi,k,s)) =  4 + 2*s                                                                                          
                                                >= 4 + 2*s                                                                                          
                                                =  Term_sub(Term_var(x),s)                                                                          
        
        Term_sub(Term_var(x),Cons_usual(y,m,s)) =  6 + 2*m + 2*s + 2*y                                                                              
                                                >= m                                                                                                
                                                =  m                                                                                                
        
        Term_sub(Term_var(x),Cons_usual(y,m,s)) =  6 + 2*m + 2*s + 2*y                                                                              
                                                >= 4 + 2*s                                                                                          
                                                =  Term_sub(Term_var(x),s)                                                                          
        
                     Term_sub(Term_var(x),Id()) =  4                                                                                                
                                                >= 1                                                                                                
                                                =  Term_var(x)                                                                                      
        
* Step 9: EmptyProcessor WORST_CASE(?,O(1))
    + Considered Problem:
        - Weak TRS:
            Concat(Cons_sum(xi,k,s),t) -> Cons_sum(xi,k,Concat(s,t))
            Concat(Cons_usual(x,m,s),t) -> Cons_usual(x,Term_sub(m,t),Concat(s,t))
            Concat(Id(),s) -> s
            Frozen(m,Sum_constant(Left()),n,s) -> Term_sub(m,s)
            Frozen(m,Sum_constant(Right()),n,s) -> Term_sub(n,s)
            Frozen(m,Sum_term_var(xi),n,s) -> Case(Term_sub(m,s),xi,Term_sub(n,s))
            Sum_sub(xi,Cons_sum(psi,k,s)) -> Sum_constant(k)
            Sum_sub(xi,Cons_sum(psi,k,s)) -> Sum_sub(xi,s)
            Sum_sub(xi,Cons_usual(y,m,s)) -> Sum_sub(xi,s)
            Sum_sub(xi,Id()) -> Sum_term_var(xi)
            Term_sub(Case(m,xi,n),s) -> Frozen(m,Sum_sub(xi,s),n,s)
            Term_sub(Term_app(m,n),s) -> Term_app(Term_sub(m,s),Term_sub(n,s))
            Term_sub(Term_inl(m),s) -> Term_inl(Term_sub(m,s))
            Term_sub(Term_inr(m),s) -> Term_inr(Term_sub(m,s))
            Term_sub(Term_pair(m,n),s) -> Term_pair(Term_sub(m,s),Term_sub(n,s))
            Term_sub(Term_var(x),Cons_sum(xi,k,s)) -> Term_sub(Term_var(x),s)
            Term_sub(Term_var(x),Cons_usual(y,m,s)) -> m
            Term_sub(Term_var(x),Cons_usual(y,m,s)) -> Term_sub(Term_var(x),s)
            Term_sub(Term_var(x),Id()) -> Term_var(x)
        - Signature:
            {Concat/2,Frozen/4,Sum_sub/2,Term_sub/2} / {Case/3,Cons_sum/3,Cons_usual/3,Id/0,Left/0,Right/0
            ,Sum_constant/1,Sum_term_var/1,Term_app/2,Term_inl/1,Term_inr/1,Term_pair/2,Term_var/1}
        - Obligation:
            innermost runtime complexity wrt. defined symbols {Concat,Frozen,Sum_sub,Term_sub} and constructors {Case
            ,Cons_sum,Cons_usual,Id,Left,Right,Sum_constant,Sum_term_var,Term_app,Term_inl,Term_inr,Term_pair,Term_var}
    + Applied Processor:
        EmptyProcessor
    + Details:
        The problem is already closed. The intended complexity is O(1).

WORST_CASE(?,O(n^2))