MAYBE
* Step 1: TrivialSCCs MAYBE
    + Considered Problem:
        Rules:
          0. f3(A,B,C,D) -> f1(0,B,C,D)         True                                (1,1)
          1. f1(A,B,C,D) -> f2(A,B,C,E)         [B >= C]                            (?,1)
          2. f1(A,B,C,D) -> f2(1,1 + B,C,E)     [1 + B = C && A = 0]                (?,1)
          3. f1(A,B,C,D) -> f1(0,1 + B,1 + C,D) [C >= 2 + B && C >= 1 + B && A = 0] (?,1)
        Signature:
          {(f1,4);(f2,4);(f3,4)}
        Flow Graph:
          [0->{1,2,3},1->{},2->{},3->{1,2,3}]
        
    + Applied Processor:
        TrivialSCCs
    + Details:
        All trivial SCCs of the transition graph admit timebound 1.
* Step 2: UnsatPaths MAYBE
    + Considered Problem:
        Rules:
          0. f3(A,B,C,D) -> f1(0,B,C,D)         True                                (1,1)
          1. f1(A,B,C,D) -> f2(A,B,C,E)         [B >= C]                            (1,1)
          2. f1(A,B,C,D) -> f2(1,1 + B,C,E)     [1 + B = C && A = 0]                (1,1)
          3. f1(A,B,C,D) -> f1(0,1 + B,1 + C,D) [C >= 2 + B && C >= 1 + B && A = 0] (?,1)
        Signature:
          {(f1,4);(f2,4);(f3,4)}
        Flow Graph:
          [0->{1,2,3},1->{},2->{},3->{1,2,3}]
        
    + Applied Processor:
        UnsatPaths
    + Details:
        We remove following edges from the transition graph: [(3,1),(3,2)]
* Step 3: AddSinks MAYBE
    + Considered Problem:
        Rules:
          0. f3(A,B,C,D) -> f1(0,B,C,D)         True                                (1,1)
          1. f1(A,B,C,D) -> f2(A,B,C,E)         [B >= C]                            (1,1)
          2. f1(A,B,C,D) -> f2(1,1 + B,C,E)     [1 + B = C && A = 0]                (1,1)
          3. f1(A,B,C,D) -> f1(0,1 + B,1 + C,D) [C >= 2 + B && C >= 1 + B && A = 0] (?,1)
        Signature:
          {(f1,4);(f2,4);(f3,4)}
        Flow Graph:
          [0->{1,2,3},1->{},2->{},3->{3}]
        
    + Applied Processor:
        AddSinks
    + Details:
        ()
* Step 4: UnsatPaths MAYBE
    + Considered Problem:
        Rules:
          0. f3(A,B,C,D) -> f1(0,B,C,D)         True                                (1,1)
          1. f1(A,B,C,D) -> f2(A,B,C,E)         [B >= C]                            (?,1)
          2. f1(A,B,C,D) -> f2(1,1 + B,C,E)     [1 + B = C && A = 0]                (?,1)
          3. f1(A,B,C,D) -> f1(0,1 + B,1 + C,D) [C >= 2 + B && C >= 1 + B && A = 0] (?,1)
          4. f1(A,B,C,D) -> exitus616(A,B,C,D)  True                                (?,1)
        Signature:
          {(exitus616,4);(f1,4);(f2,4);(f3,4)}
        Flow Graph:
          [0->{1,2,3,4},1->{},2->{},3->{1,2,3,4},4->{}]
        
    + Applied Processor:
        UnsatPaths
    + Details:
        We remove following edges from the transition graph: [(3,1),(3,2)]
* Step 5: Failure MAYBE
  + Considered Problem:
      Rules:
        0. f3(A,B,C,D) -> f1(0,B,C,D)         True                                (1,1)
        1. f1(A,B,C,D) -> f2(A,B,C,E)         [B >= C]                            (?,1)
        2. f1(A,B,C,D) -> f2(1,1 + B,C,E)     [1 + B = C && A = 0]                (?,1)
        3. f1(A,B,C,D) -> f1(0,1 + B,1 + C,D) [C >= 2 + B && C >= 1 + B && A = 0] (?,1)
        4. f1(A,B,C,D) -> exitus616(A,B,C,D)  True                                (?,1)
      Signature:
        {(exitus616,4);(f1,4);(f2,4);(f3,4)}
      Flow Graph:
        [0->{1,2,3,4},1->{},2->{},3->{3,4},4->{}]
      
  + Applied Processor:
      LooptreeTransformer
  + Details:
      We construct a looptree:
        P: [0,1,2,3,4]
        |
        `- p:[3] c: []
MAYBE