We are left with following problem, upon which TcT provides the
certificate YES(O(1),O(n^1)).

Strict Trs:
  { even(Cons(x', Cons(x, xs))) -> even(xs)
  , even(Cons(x, Nil())) -> False()
  , even(Nil()) -> True()
  , lte(Cons(x', xs'), Cons(x, xs)) -> lte(xs', xs)
  , lte(Cons(x, xs), Nil()) -> False()
  , lte(Nil(), y) -> True()
  , notEmpty(Cons(x, xs)) -> True()
  , notEmpty(Nil()) -> False()
  , goal(x, y) -> and(lte(x, y), even(x)) }
Weak Trs:
  { and(True(), True()) -> True()
  , and(True(), False()) -> False()
  , and(False(), True()) -> False()
  , and(False(), False()) -> False() }
Obligation:
  innermost runtime complexity
Answer:
  YES(O(1),O(n^1))

We add the following weak dependency pairs:

Strict DPs:
  { even^#(Cons(x', Cons(x, xs))) -> c_1(even^#(xs))
  , even^#(Cons(x, Nil())) -> c_2()
  , even^#(Nil()) -> c_3()
  , lte^#(Cons(x', xs'), Cons(x, xs)) -> c_4(lte^#(xs', xs))
  , lte^#(Cons(x, xs), Nil()) -> c_5()
  , lte^#(Nil(), y) -> c_6()
  , notEmpty^#(Cons(x, xs)) -> c_7()
  , notEmpty^#(Nil()) -> c_8()
  , goal^#(x, y) -> c_9(and^#(lte(x, y), even(x))) }
Weak DPs:
  { and^#(True(), True()) -> c_10()
  , and^#(True(), False()) -> c_11()
  , and^#(False(), True()) -> c_12()
  , and^#(False(), False()) -> c_13() }

and mark the set of starting terms.

We are left with following problem, upon which TcT provides the
certificate YES(O(1),O(n^1)).

Strict DPs:
  { even^#(Cons(x', Cons(x, xs))) -> c_1(even^#(xs))
  , even^#(Cons(x, Nil())) -> c_2()
  , even^#(Nil()) -> c_3()
  , lte^#(Cons(x', xs'), Cons(x, xs)) -> c_4(lte^#(xs', xs))
  , lte^#(Cons(x, xs), Nil()) -> c_5()
  , lte^#(Nil(), y) -> c_6()
  , notEmpty^#(Cons(x, xs)) -> c_7()
  , notEmpty^#(Nil()) -> c_8()
  , goal^#(x, y) -> c_9(and^#(lte(x, y), even(x))) }
Strict Trs:
  { even(Cons(x', Cons(x, xs))) -> even(xs)
  , even(Cons(x, Nil())) -> False()
  , even(Nil()) -> True()
  , lte(Cons(x', xs'), Cons(x, xs)) -> lte(xs', xs)
  , lte(Cons(x, xs), Nil()) -> False()
  , lte(Nil(), y) -> True()
  , notEmpty(Cons(x, xs)) -> True()
  , notEmpty(Nil()) -> False()
  , goal(x, y) -> and(lte(x, y), even(x)) }
Weak DPs:
  { and^#(True(), True()) -> c_10()
  , and^#(True(), False()) -> c_11()
  , and^#(False(), True()) -> c_12()
  , and^#(False(), False()) -> c_13() }
Weak Trs:
  { and(True(), True()) -> True()
  , and(True(), False()) -> False()
  , and(False(), True()) -> False()
  , and(False(), False()) -> False() }
Obligation:
  innermost runtime complexity
Answer:
  YES(O(1),O(n^1))

We replace rewrite rules by usable rules:

  Strict Usable Rules:
    { even(Cons(x', Cons(x, xs))) -> even(xs)
    , even(Cons(x, Nil())) -> False()
    , even(Nil()) -> True()
    , lte(Cons(x', xs'), Cons(x, xs)) -> lte(xs', xs)
    , lte(Cons(x, xs), Nil()) -> False()
    , lte(Nil(), y) -> True() }

We are left with following problem, upon which TcT provides the
certificate YES(O(1),O(n^1)).

Strict DPs:
  { even^#(Cons(x', Cons(x, xs))) -> c_1(even^#(xs))
  , even^#(Cons(x, Nil())) -> c_2()
  , even^#(Nil()) -> c_3()
  , lte^#(Cons(x', xs'), Cons(x, xs)) -> c_4(lte^#(xs', xs))
  , lte^#(Cons(x, xs), Nil()) -> c_5()
  , lte^#(Nil(), y) -> c_6()
  , notEmpty^#(Cons(x, xs)) -> c_7()
  , notEmpty^#(Nil()) -> c_8()
  , goal^#(x, y) -> c_9(and^#(lte(x, y), even(x))) }
Strict Trs:
  { even(Cons(x', Cons(x, xs))) -> even(xs)
  , even(Cons(x, Nil())) -> False()
  , even(Nil()) -> True()
  , lte(Cons(x', xs'), Cons(x, xs)) -> lte(xs', xs)
  , lte(Cons(x, xs), Nil()) -> False()
  , lte(Nil(), y) -> True() }
Weak DPs:
  { and^#(True(), True()) -> c_10()
  , and^#(True(), False()) -> c_11()
  , and^#(False(), True()) -> c_12()
  , and^#(False(), False()) -> c_13() }
Obligation:
  innermost runtime complexity
Answer:
  YES(O(1),O(n^1))

The weightgap principle applies (using the following constant
growth matrix-interpretation)

The following argument positions are usable:
  Uargs(c_1) = {1}, Uargs(c_4) = {1}, Uargs(c_9) = {1},
  Uargs(and^#) = {1, 2}

TcT has computed the following constructor-restricted matrix
interpretation.

        [even](x1) = [0 1] x1 + [2]           
                     [0 0]      [0]           
                                              
     [lte](x1, x2) = [0 1] x1 + [0 1] x2 + [2]
                     [0 0]      [0 0]      [0]
                                              
            [True] = [0]                      
                     [0]                      
                                              
    [Cons](x1, x2) = [0 0] x2 + [0]           
                     [0 1]      [1]           
                                              
             [Nil] = [0]                      
                     [2]                      
                                              
           [False] = [0]                      
                     [0]                      
                                              
      [even^#](x1) = [0]                      
                     [0]                      
                                              
         [c_1](x1) = [1 0] x1 + [0]           
                     [0 1]      [0]           
                                              
             [c_2] = [0]                      
                     [0]                      
                                              
             [c_3] = [0]                      
                     [0]                      
                                              
   [lte^#](x1, x2) = [0]                      
                     [0]                      
                                              
         [c_4](x1) = [1 0] x1 + [0]           
                     [0 1]      [0]           
                                              
             [c_5] = [0]                      
                     [0]                      
                                              
             [c_6] = [0]                      
                     [0]                      
                                              
  [notEmpty^#](x1) = [0]                      
                     [0]                      
                                              
             [c_7] = [0]                      
                     [0]                      
                                              
             [c_8] = [0]                      
                     [0]                      
                                              
  [goal^#](x1, x2) = [2 2] x1 + [1 2] x2 + [0]
                     [0 0]      [0 0]      [0]
                                              
         [c_9](x1) = [1 0] x1 + [0]           
                     [0 1]      [0]           
                                              
   [and^#](x1, x2) = [1 0] x1 + [1 0] x2 + [0]
                     [0 0]      [0 0]      [0]
                                              
            [c_10] = [0]                      
                     [0]                      
                                              
            [c_11] = [0]                      
                     [0]                      
                                              
            [c_12] = [0]                      
                     [0]                      
                                              
            [c_13] = [0]                      
                     [0]                      

The order satisfies the following ordering constraints:

        [even(Cons(x', Cons(x, xs)))] =  [0 1] xs + [4]                  
                                         [0 0]      [0]                  
                                      >  [0 1] xs + [2]                  
                                         [0 0]      [0]                  
                                      =  [even(xs)]                      
                                                                         
               [even(Cons(x, Nil()))] =  [5]                             
                                         [0]                             
                                      >  [0]                             
                                         [0]                             
                                      =  [False()]                       
                                                                         
                        [even(Nil())] =  [4]                             
                                         [0]                             
                                      >  [0]                             
                                         [0]                             
                                      =  [True()]                        
                                                                         
    [lte(Cons(x', xs'), Cons(x, xs))] =  [0 1] xs' + [0 1] xs + [4]      
                                         [0 0]       [0 0]      [0]      
                                      >  [0 1] xs' + [0 1] xs + [2]      
                                         [0 0]       [0 0]      [0]      
                                      =  [lte(xs', xs)]                  
                                                                         
            [lte(Cons(x, xs), Nil())] =  [0 1] xs + [5]                  
                                         [0 0]      [0]                  
                                      >  [0]                             
                                         [0]                             
                                      =  [False()]                       
                                                                         
                      [lte(Nil(), y)] =  [0 1] y + [4]                   
                                         [0 0]     [0]                   
                                      >  [0]                             
                                         [0]                             
                                      =  [True()]                        
                                                                         
      [even^#(Cons(x', Cons(x, xs)))] =  [0]                             
                                         [0]                             
                                      >= [0]                             
                                         [0]                             
                                      =  [c_1(even^#(xs))]               
                                                                         
             [even^#(Cons(x, Nil()))] =  [0]                             
                                         [0]                             
                                      >= [0]                             
                                         [0]                             
                                      =  [c_2()]                         
                                                                         
                      [even^#(Nil())] =  [0]                             
                                         [0]                             
                                      >= [0]                             
                                         [0]                             
                                      =  [c_3()]                         
                                                                         
  [lte^#(Cons(x', xs'), Cons(x, xs))] =  [0]                             
                                         [0]                             
                                      >= [0]                             
                                         [0]                             
                                      =  [c_4(lte^#(xs', xs))]           
                                                                         
          [lte^#(Cons(x, xs), Nil())] =  [0]                             
                                         [0]                             
                                      >= [0]                             
                                         [0]                             
                                      =  [c_5()]                         
                                                                         
                    [lte^#(Nil(), y)] =  [0]                             
                                         [0]                             
                                      >= [0]                             
                                         [0]                             
                                      =  [c_6()]                         
                                                                         
            [notEmpty^#(Cons(x, xs))] =  [0]                             
                                         [0]                             
                                      >= [0]                             
                                         [0]                             
                                      =  [c_7()]                         
                                                                         
                  [notEmpty^#(Nil())] =  [0]                             
                                         [0]                             
                                      >= [0]                             
                                         [0]                             
                                      =  [c_8()]                         
                                                                         
                       [goal^#(x, y)] =  [2 2] x + [1 2] y + [0]         
                                         [0 0]     [0 0]     [0]         
                                      ?  [0 2] x + [0 1] y + [4]         
                                         [0 0]     [0 0]     [0]         
                                      =  [c_9(and^#(lte(x, y), even(x)))]
                                                                         
              [and^#(True(), True())] =  [0]                             
                                         [0]                             
                                      >= [0]                             
                                         [0]                             
                                      =  [c_10()]                        
                                                                         
             [and^#(True(), False())] =  [0]                             
                                         [0]                             
                                      >= [0]                             
                                         [0]                             
                                      =  [c_11()]                        
                                                                         
             [and^#(False(), True())] =  [0]                             
                                         [0]                             
                                      >= [0]                             
                                         [0]                             
                                      =  [c_12()]                        
                                                                         
            [and^#(False(), False())] =  [0]                             
                                         [0]                             
                                      >= [0]                             
                                         [0]                             
                                      =  [c_13()]                        
                                                                         

Further, it can be verified that all rules not oriented are covered by the weightgap condition.

We are left with following problem, upon which TcT provides the
certificate YES(O(1),O(n^1)).

Strict DPs:
  { even^#(Cons(x', Cons(x, xs))) -> c_1(even^#(xs))
  , even^#(Cons(x, Nil())) -> c_2()
  , even^#(Nil()) -> c_3()
  , lte^#(Cons(x', xs'), Cons(x, xs)) -> c_4(lte^#(xs', xs))
  , lte^#(Cons(x, xs), Nil()) -> c_5()
  , lte^#(Nil(), y) -> c_6()
  , notEmpty^#(Cons(x, xs)) -> c_7()
  , notEmpty^#(Nil()) -> c_8()
  , goal^#(x, y) -> c_9(and^#(lte(x, y), even(x))) }
Weak DPs:
  { and^#(True(), True()) -> c_10()
  , and^#(True(), False()) -> c_11()
  , and^#(False(), True()) -> c_12()
  , and^#(False(), False()) -> c_13() }
Weak Trs:
  { even(Cons(x', Cons(x, xs))) -> even(xs)
  , even(Cons(x, Nil())) -> False()
  , even(Nil()) -> True()
  , lte(Cons(x', xs'), Cons(x, xs)) -> lte(xs', xs)
  , lte(Cons(x, xs), Nil()) -> False()
  , lte(Nil(), y) -> True() }
Obligation:
  innermost runtime complexity
Answer:
  YES(O(1),O(n^1))

We estimate the number of application of {2,3,5,6,7,8,9} by
applications of Pre({2,3,5,6,7,8,9}) = {1,4}. Here rules are
labeled as follows:

  DPs:
    { 1: even^#(Cons(x', Cons(x, xs))) -> c_1(even^#(xs))
    , 2: even^#(Cons(x, Nil())) -> c_2()
    , 3: even^#(Nil()) -> c_3()
    , 4: lte^#(Cons(x', xs'), Cons(x, xs)) -> c_4(lte^#(xs', xs))
    , 5: lte^#(Cons(x, xs), Nil()) -> c_5()
    , 6: lte^#(Nil(), y) -> c_6()
    , 7: notEmpty^#(Cons(x, xs)) -> c_7()
    , 8: notEmpty^#(Nil()) -> c_8()
    , 9: goal^#(x, y) -> c_9(and^#(lte(x, y), even(x)))
    , 10: and^#(True(), True()) -> c_10()
    , 11: and^#(True(), False()) -> c_11()
    , 12: and^#(False(), True()) -> c_12()
    , 13: and^#(False(), False()) -> c_13() }

We are left with following problem, upon which TcT provides the
certificate YES(O(1),O(n^1)).

Strict DPs:
  { even^#(Cons(x', Cons(x, xs))) -> c_1(even^#(xs))
  , lte^#(Cons(x', xs'), Cons(x, xs)) -> c_4(lte^#(xs', xs)) }
Weak DPs:
  { even^#(Cons(x, Nil())) -> c_2()
  , even^#(Nil()) -> c_3()
  , lte^#(Cons(x, xs), Nil()) -> c_5()
  , lte^#(Nil(), y) -> c_6()
  , notEmpty^#(Cons(x, xs)) -> c_7()
  , notEmpty^#(Nil()) -> c_8()
  , goal^#(x, y) -> c_9(and^#(lte(x, y), even(x)))
  , and^#(True(), True()) -> c_10()
  , and^#(True(), False()) -> c_11()
  , and^#(False(), True()) -> c_12()
  , and^#(False(), False()) -> c_13() }
Weak Trs:
  { even(Cons(x', Cons(x, xs))) -> even(xs)
  , even(Cons(x, Nil())) -> False()
  , even(Nil()) -> True()
  , lte(Cons(x', xs'), Cons(x, xs)) -> lte(xs', xs)
  , lte(Cons(x, xs), Nil()) -> False()
  , lte(Nil(), y) -> True() }
Obligation:
  innermost runtime complexity
Answer:
  YES(O(1),O(n^1))

The following weak DPs constitute a sub-graph of the DG that is
closed under successors. The DPs are removed.

{ even^#(Cons(x, Nil())) -> c_2()
, even^#(Nil()) -> c_3()
, lte^#(Cons(x, xs), Nil()) -> c_5()
, lte^#(Nil(), y) -> c_6()
, notEmpty^#(Cons(x, xs)) -> c_7()
, notEmpty^#(Nil()) -> c_8()
, goal^#(x, y) -> c_9(and^#(lte(x, y), even(x)))
, and^#(True(), True()) -> c_10()
, and^#(True(), False()) -> c_11()
, and^#(False(), True()) -> c_12()
, and^#(False(), False()) -> c_13() }

We are left with following problem, upon which TcT provides the
certificate YES(O(1),O(n^1)).

Strict DPs:
  { even^#(Cons(x', Cons(x, xs))) -> c_1(even^#(xs))
  , lte^#(Cons(x', xs'), Cons(x, xs)) -> c_4(lte^#(xs', xs)) }
Weak Trs:
  { even(Cons(x', Cons(x, xs))) -> even(xs)
  , even(Cons(x, Nil())) -> False()
  , even(Nil()) -> True()
  , lte(Cons(x', xs'), Cons(x, xs)) -> lte(xs', xs)
  , lte(Cons(x, xs), Nil()) -> False()
  , lte(Nil(), y) -> True() }
Obligation:
  innermost runtime complexity
Answer:
  YES(O(1),O(n^1))

No rule is usable, rules are removed from the input problem.

We are left with following problem, upon which TcT provides the
certificate YES(O(1),O(n^1)).

Strict DPs:
  { even^#(Cons(x', Cons(x, xs))) -> c_1(even^#(xs))
  , lte^#(Cons(x', xs'), Cons(x, xs)) -> c_4(lte^#(xs', xs)) }
Obligation:
  innermost runtime complexity
Answer:
  YES(O(1),O(n^1))

We use the processor 'Small Polynomial Path Order (PS,1-bounded)'
to orient following rules strictly.

DPs:
  { 1: even^#(Cons(x', Cons(x, xs))) -> c_1(even^#(xs))
  , 2: lte^#(Cons(x', xs'), Cons(x, xs)) -> c_4(lte^#(xs', xs)) }

Sub-proof:
----------
  The input was oriented with the instance of 'Small Polynomial Path
  Order (PS,1-bounded)' as induced by the safe mapping
  
   safe(Cons) = {1, 2}, safe(even^#) = {}, safe(c_1) = {},
   safe(lte^#) = {2}, safe(c_4) = {}
  
  and precedence
  
   empty .
  
  Following symbols are considered recursive:
  
   {even^#, lte^#}
  
  The recursion depth is 1.
  
  Further, following argument filtering is employed:
  
   pi(Cons) = [2], pi(even^#) = [1], pi(c_1) = [1], pi(lte^#) = [1],
   pi(c_4) = [1]
  
  Usable defined function symbols are a subset of:
  
   {even^#, lte^#}
  
  For your convenience, here are the satisfied ordering constraints:
  
        pi(even^#(Cons(x', Cons(x, xs)))) = even^#(Cons(; Cons(; xs));)
                                          > c_1(even^#(xs;);)          
                                          = pi(c_1(even^#(xs)))        
                                                                       
    pi(lte^#(Cons(x', xs'), Cons(x, xs))) = lte^#(Cons(; xs');)        
                                          > c_4(lte^#(xs';);)          
                                          = pi(c_4(lte^#(xs', xs)))    
                                                                       

The strictly oriented rules are moved into the weak component.

We are left with following problem, upon which TcT provides the
certificate YES(O(1),O(1)).

Weak DPs:
  { even^#(Cons(x', Cons(x, xs))) -> c_1(even^#(xs))
  , lte^#(Cons(x', xs'), Cons(x, xs)) -> c_4(lte^#(xs', xs)) }
Obligation:
  innermost runtime complexity
Answer:
  YES(O(1),O(1))

The following weak DPs constitute a sub-graph of the DG that is
closed under successors. The DPs are removed.

{ even^#(Cons(x', Cons(x, xs))) -> c_1(even^#(xs))
, lte^#(Cons(x', xs'), Cons(x, xs)) -> c_4(lte^#(xs', xs)) }

We are left with following problem, upon which TcT provides the
certificate YES(O(1),O(1)).

Rules: Empty
Obligation:
  innermost runtime complexity
Answer:
  YES(O(1),O(1))

Empty rules are trivially bounded

Hurray, we answered YES(O(1),O(n^1))