MAYBE
* Step 1: AddSinks MAYBE
    + Considered Problem:
        Rules:
          0. f2(A,B,C,D) -> f0(0,B,C,D)      True                  (1,1)
          1. f0(A,B,C,D) -> f0(-1 + A,B,A,D) [-1*A >= 0 && 9 >= A] (?,1)
        Signature:
          {(f0,4);(f2,4)}
        Flow Graph:
          [0->{1},1->{1}]
        
    + Applied Processor:
        AddSinks
    + Details:
        ()
* Step 2: Failure MAYBE
  + Considered Problem:
      Rules:
        0. f2(A,B,C,D) -> f0(0,B,C,D)        True                  (1,1)
        1. f0(A,B,C,D) -> f0(-1 + A,B,A,D)   [-1*A >= 0 && 9 >= A] (?,1)
        2. f0(A,B,C,D) -> exitus616(A,B,C,D) True                  (?,1)
      Signature:
        {(exitus616,4);(f0,4);(f2,4)}
      Flow Graph:
        [0->{1,2},1->{1,2},2->{}]
      
  + Applied Processor:
      LooptreeTransformer
  + Details:
      We construct a looptree:
        P: [0,1,2]
        |
        `- p:[1] c: []
MAYBE