YES
(ignored inputs)COMMENT doi:10.1007/3-540-61064-2_39 [10] Example 9 submitted by: Takahito Aoto , Junichi Yoshida , and Yoshihito Toyama
Rewrite Rules:
   [ f(a) -> f(f(a)),
     a -> b,
     f(?x) -> f(b) ]
Apply Direct Methods...
Inner CPs:
   [ f(b) = f(f(a)) ]
Outer CPs:
   [ f(f(a)) = f(b) ]
not Overlay, check Termination...
unknown/not Terminating
unknown Knuth & Bendix
Linear
unknown Development Closed
Strongly Closed
Direct Methods: CR

Combined result: CR
36.trs: Success(CR)
(0 msec.)