(ignored inputs)COMMENT doi:10.1017/CBO9781139172752 [4] Exercise 6.5 ( a ) submitted by: Takahito Aoto , Junichi Yoshida , and Yoshihito Toyama
Rewrite Rules:
   [ f(g(f(?x))) -> ?x,
     f(g(?x)) -> g(f(?x)) ]
Apply Direct Methods...
Inner CPs:
   [ f(g(g(f(?x_1)))) = g(?x_1),
     f(g(?x)) = g(f(?x)) ]
Outer CPs:
   [ ?x = g(f(f(?x))) ]
not Overlay, check Termination...
Terminating, not WCR
Knuth & Bendix
Direct Methods: not CR

Combined result: not CR
10.trs: Success(not CR)
NO
(4 msec.)