* Step 1: Sum WORST_CASE(Omega(n^1),?)
    + Considered Problem:
        - Strict TRS:
            active(c()) -> mark(b())
            active(f(X1,X2,X3)) -> f(X1,active(X2),X3)
            active(f(b(),X,c())) -> mark(f(X,c(),X))
            f(X1,mark(X2),X3) -> mark(f(X1,X2,X3))
            f(ok(X1),ok(X2),ok(X3)) -> ok(f(X1,X2,X3))
            proper(b()) -> ok(b())
            proper(c()) -> ok(c())
            proper(f(X1,X2,X3)) -> f(proper(X1),proper(X2),proper(X3))
            top(mark(X)) -> top(proper(X))
            top(ok(X)) -> top(active(X))
        - Signature:
            {active/1,f/3,proper/1,top/1} / {b/0,c/0,mark/1,ok/1}
        - Obligation:
            innermost runtime complexity wrt. defined symbols {active,f,proper,top} and constructors {b,c,mark,ok}
    + Applied Processor:
        Sum {left = someStrategy, right = someStrategy}
    + Details:
        ()
* Step 2: DecreasingLoops WORST_CASE(Omega(n^1),?)
    + Considered Problem:
        - Strict TRS:
            active(c()) -> mark(b())
            active(f(X1,X2,X3)) -> f(X1,active(X2),X3)
            active(f(b(),X,c())) -> mark(f(X,c(),X))
            f(X1,mark(X2),X3) -> mark(f(X1,X2,X3))
            f(ok(X1),ok(X2),ok(X3)) -> ok(f(X1,X2,X3))
            proper(b()) -> ok(b())
            proper(c()) -> ok(c())
            proper(f(X1,X2,X3)) -> f(proper(X1),proper(X2),proper(X3))
            top(mark(X)) -> top(proper(X))
            top(ok(X)) -> top(active(X))
        - Signature:
            {active/1,f/3,proper/1,top/1} / {b/0,c/0,mark/1,ok/1}
        - Obligation:
            innermost runtime complexity wrt. defined symbols {active,f,proper,top} and constructors {b,c,mark,ok}
    + Applied Processor:
        DecreasingLoops {bound = AnyLoop, narrow = 10}
    + Details:
        The system has following decreasing Loops:
          f(x,y,z){y -> mark(y)} =
            f(x,mark(y),z) ->^+ mark(f(x,y,z))
              = C[f(x,y,z) = f(x,y,z){}]

WORST_CASE(Omega(n^1),?)