(ignored inputs)COMMENT [111] p. 29
Rewrite Rules:
   [ f(f(f(?x))) -> a,
     f(f(a)) -> a,
     f(a) -> a,
     f(f(g(g(?x)))) -> f(a),
     g(f(a)) -> a,
     g(a) -> a ]
Apply Direct Methods...
Inner CPs:
   [ f(a) = a,
     f(f(a)) = a,
     f(f(a)) = a,
     f(f(a)) = a,
     f(f(f(a))) = a,
     f(a) = a,
     f(f(g(a))) = f(a),
     f(f(g(a))) = f(a),
     g(a) = a,
     f(a) = a,
     f(f(a)) = a ]
Outer CPs:
   [  ]
not Overlay, check Termination...
Terminating, WCR
Knuth & Bendix
Direct Methods: CR

Combined result: CR
506.trs: Success(CR)
YES
(0 msec.)