* Step 1: Sum WORST_CASE(Omega(n^1),?)
    + Considered Problem:
        - Strict TRS:
            dbl(0()) -> 0()
            dbl(s(X)) -> s(s(dbl(X)))
            dbls(cons(X,Y)) -> cons(dbl(X),dbls(Y))
            dbls(nil()) -> nil()
            from(X) -> cons(X,from(s(X)))
            indx(cons(X,Y),Z) -> cons(sel(X,Z),indx(Y,Z))
            indx(nil(),X) -> nil()
            sel(0(),cons(X,Y)) -> X
            sel(s(X),cons(Y,Z)) -> sel(X,Z)
        - Signature:
            {dbl/1,dbls/1,from/1,indx/2,sel/2} / {0/0,cons/2,nil/0,s/1}
        - Obligation:
            innermost runtime complexity wrt. defined symbols {dbl,dbls,from,indx,sel} and constructors {0,cons,nil,s}
    + Applied Processor:
        Sum {left = someStrategy, right = someStrategy}
    + Details:
        ()
* Step 2: DecreasingLoops WORST_CASE(Omega(n^1),?)
    + Considered Problem:
        - Strict TRS:
            dbl(0()) -> 0()
            dbl(s(X)) -> s(s(dbl(X)))
            dbls(cons(X,Y)) -> cons(dbl(X),dbls(Y))
            dbls(nil()) -> nil()
            from(X) -> cons(X,from(s(X)))
            indx(cons(X,Y),Z) -> cons(sel(X,Z),indx(Y,Z))
            indx(nil(),X) -> nil()
            sel(0(),cons(X,Y)) -> X
            sel(s(X),cons(Y,Z)) -> sel(X,Z)
        - Signature:
            {dbl/1,dbls/1,from/1,indx/2,sel/2} / {0/0,cons/2,nil/0,s/1}
        - Obligation:
            innermost runtime complexity wrt. defined symbols {dbl,dbls,from,indx,sel} and constructors {0,cons,nil,s}
    + Applied Processor:
        DecreasingLoops {bound = AnyLoop, narrow = 10}
    + Details:
        The system has following decreasing Loops:
          dbl(x){x -> s(x)} =
            dbl(s(x)) ->^+ s(s(dbl(x)))
              = C[dbl(x) = dbl(x){}]

WORST_CASE(Omega(n^1),?)