* Step 1: Sum WORST_CASE(Omega(n^1),?)
    + Considered Problem:
        - Strict TRS:
            f(x,a(b(y))) -> f(c(d(x)),y)
            f(c(x),y) -> f(x,a(y))
            f(d(x),y) -> f(x,b(y))
        - Signature:
            {f/2} / {a/1,b/1,c/1,d/1}
        - Obligation:
            innermost runtime complexity wrt. defined symbols {f} and constructors {a,b,c,d}
    + Applied Processor:
        Sum {left = someStrategy, right = someStrategy}
    + Details:
        ()
* Step 2: DecreasingLoops WORST_CASE(Omega(n^1),?)
    + Considered Problem:
        - Strict TRS:
            f(x,a(b(y))) -> f(c(d(x)),y)
            f(c(x),y) -> f(x,a(y))
            f(d(x),y) -> f(x,b(y))
        - Signature:
            {f/2} / {a/1,b/1,c/1,d/1}
        - Obligation:
            innermost runtime complexity wrt. defined symbols {f} and constructors {a,b,c,d}
    + Applied Processor:
        DecreasingLoops {bound = AnyLoop, narrow = 10}
    + Details:
        The system has following decreasing Loops:
          f(x,y){y -> a(b(y))} =
            f(x,a(b(y))) ->^+ f(c(d(x)),y)
              = C[f(c(d(x)),y) = f(x,y){x -> c(d(x))}]

WORST_CASE(Omega(n^1),?)