MAYBE
* Step 1: FromIts MAYBE
    + Considered Problem:
        Rules:
          0. f3(A,B) -> f0(0,B)      True                                                                                      (1,1)
          1. f0(A,B) -> f0(A,-1 + B) [-1*A >= 0 && A >= 0 && B >= 1]                                                           (?,1)
          2. f4(A,B) -> f4(A,B)      [-1*B >= 0 && 1 + A + -1*B >= 0 && -1 + -1*A + -1*B >= 0 && -1 + -1*A >= 0 && 1 + A >= 0] (?,1)
          3. f0(A,B) -> f4(-1,B)     [-1*A >= 0 && A >= 0 && 0 >= B]                                                           (?,1)
        Signature:
          {(f0,2);(f3,2);(f4,2)}
        Flow Graph:
          [0->{1,3},1->{1,3},2->{2},3->{2}]
        
    + Applied Processor:
        FromIts
    + Details:
        ()
* Step 2: AddSinks MAYBE
    + Considered Problem:
        Rules:
          f3(A,B) -> f0(0,B)       True
          f0(A,B) -> f0(A,-1 + B)  [-1*A >= 0 && A >= 0 && B >= 1]
          f4(A,B) -> f4(A,B)       [-1*B >= 0
                                    && 1 + A + -1*B >= 0
                                    && -1 + -1*A + -1*B >= 0
                                    && -1 + -1*A >= 0
                                    && 1 + A >= 0]
          f0(A,B) -> f4(-1,B)      [-1*A >= 0 && A >= 0 && 0 >= B]
        Signature:
          {(f0,2);(f3,2);(f4,2)}
        Rule Graph:
          [0->{1,3},1->{1,3},2->{2},3->{2}]
    + Applied Processor:
        AddSinks
    + Details:
        ()
* Step 3: Failure MAYBE
  + Considered Problem:
      Rules:
        f3(A,B) -> f0(0,B)         True
        f0(A,B) -> f0(A,-1 + B)    [-1*A >= 0 && A >= 0 && B >= 1]
        f4(A,B) -> f4(A,B)         [-1*B >= 0
                                    && 1 + A + -1*B >= 0
                                    && -1 + -1*A + -1*B >= 0
                                    && -1 + -1*A >= 0
                                    && 1 + A >= 0]
        f0(A,B) -> f4(-1,B)        [-1*A >= 0 && A >= 0 && 0 >= B]
        f4(A,B) -> exitus616(A,B)  True
      Signature:
        {(exitus616,2);(f0,2);(f3,2);(f4,2)}
      Rule Graph:
        [0->{1,3},1->{1,3},2->{2,4},3->{2}]
  + Applied Processor:
      Decompose Greedy
  + Details:
      We construct a looptree:
        P: [0,1,2,3,4]
        |
        +- p:[1] c: [1]
        |
        `- p:[2] c: []
MAYBE