MAYBE
* Step 1: 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)
      Signature:
        {(f0,4);(f2,4)}
      Flow Graph:
        [0->{1},1->{1}]
      
  + Applied Processor:
      Failing "Open problems left."
  + Details:
      Open problems left.
MAYBE