WORST_CASE(Omega(n^1),?)
* Step 1: Sum.  WORST_CASE(Omega(n^1),?)
    + Considered Problem:
        - Strict TRS:
            +'(z0,0()) -> c4()
            +'(z0,s(z1)) -> c5(+'(z0,z1))
            FIB(0()) -> c()
            FIB(s(0())) -> c1()
            FIB(s(s(z0))) -> c2(+'(fib(s(z0)),fib(z0)),FIB(s(z0)))
            FIB(s(s(z0))) -> c3(+'(fib(s(z0)),fib(z0)),FIB(z0))
        - Weak TRS:
            +(z0,0()) -> z0
            +(z0,s(z1)) -> s(+(z0,z1))
            fib(0()) -> 0()
            fib(s(0())) -> s(0())
            fib(s(s(z0))) -> +(fib(s(z0)),fib(z0))
        - Signature:
            {+/2,+'/2,FIB/1,fib/1} / {0/0,c/0,c1/0,c2/2,c3/2,c4/0,c5/1,s/1}
        - Obligation:
            innermost runtime complexity wrt. defined symbols {+,+',FIB,fib} and constructors {0,c,c1,c2,c3,c4,c5,s}
    + Applied Processor:
        Sum {left = someStrategy, right = someStrategy}
    + Details:
        ()
* Step 2: Sum.  WORST_CASE(Omega(n^1),?)
    + Considered Problem:
        - Strict TRS:
            +'(z0,0()) -> c4()
            +'(z0,s(z1)) -> c5(+'(z0,z1))
            FIB(0()) -> c()
            FIB(s(0())) -> c1()
            FIB(s(s(z0))) -> c2(+'(fib(s(z0)),fib(z0)),FIB(s(z0)))
            FIB(s(s(z0))) -> c3(+'(fib(s(z0)),fib(z0)),FIB(z0))
        - Weak TRS:
            +(z0,0()) -> z0
            +(z0,s(z1)) -> s(+(z0,z1))
            fib(0()) -> 0()
            fib(s(0())) -> s(0())
            fib(s(s(z0))) -> +(fib(s(z0)),fib(z0))
        - Signature:
            {+/2,+'/2,FIB/1,fib/1} / {0/0,c/0,c1/0,c2/2,c3/2,c4/0,c5/1,s/1}
        - Obligation:
            innermost runtime complexity wrt. defined symbols {+,+',FIB,fib} and constructors {0,c,c1,c2,c3,c4,c5,s}
    + Applied Processor:
        Sum {left = someStrategy, right = someStrategy}
    + Details:
        ()
* Step 3: DecreasingLoops.  WORST_CASE(Omega(n^1),?)
    + Considered Problem:
        - Strict TRS:
            +'(z0,0()) -> c4()
            +'(z0,s(z1)) -> c5(+'(z0,z1))
            FIB(0()) -> c()
            FIB(s(0())) -> c1()
            FIB(s(s(z0))) -> c2(+'(fib(s(z0)),fib(z0)),FIB(s(z0)))
            FIB(s(s(z0))) -> c3(+'(fib(s(z0)),fib(z0)),FIB(z0))
        - Weak TRS:
            +(z0,0()) -> z0
            +(z0,s(z1)) -> s(+(z0,z1))
            fib(0()) -> 0()
            fib(s(0())) -> s(0())
            fib(s(s(z0))) -> +(fib(s(z0)),fib(z0))
        - Signature:
            {+/2,+'/2,FIB/1,fib/1} / {0/0,c/0,c1/0,c2/2,c3/2,c4/0,c5/1,s/1}
        - Obligation:
            innermost runtime complexity wrt. defined symbols {+,+',FIB,fib} and constructors {0,c,c1,c2,c3,c4,c5,s}
    + Applied Processor:
        DecreasingLoops {bound = AnyLoop, narrow = 10}
    + Details:
        The system has following decreasing Loops:
          +'(x,y){y -> s(y)} =
            +'(x,s(y)) ->^+ c5(+'(x,y))
              = C[+'(x,y) = +'(x,y){}]

WORST_CASE(Omega(n^1),?)