MAYBE
TRS:
 {f(a(), X) -> f(X, X),
        c() -> a(),
        c() -> b()}
 DP:
  Strict:
   {f#(a(), X) -> f#(X, X)}
  Weak:
  {f(a(), X) -> f(X, X),
         c() -> a(),
         c() -> b()}
  EDG:
   {(f#(a(), X) -> f#(X, X), f#(a(), X) -> f#(X, X))}
   SCCS:
    Scc:
     {f#(a(), X) -> f#(X, X)}
    SCC:
     Strict:
      {f#(a(), X) -> f#(X, X)}
     Weak:
     {f(a(), X) -> f(X, X),
            c() -> a(),
            c() -> b()}
     Fail