NO
(ignored inputs)COMMENT doi:10.1017/CBO9781139172752 [4] Exercise 6.5 ( d ) submitted by: Takahito Aoto , Junichi Yoshida , and Yoshihito Toyama
Rewrite Rules:
   [ f(f(?x,?y),?z) -> f(?x,f(?y,?z)),
     f(?x,1) -> ?x ]
Apply Direct Methods...
Inner CPs:
   [ f(?x_1,?z) = f(?x_1,f(1,?z)),
     f(f(?x,f(?y,?z)),?z_1) = f(f(?x,?y),f(?z,?z_1)) ]
Outer CPs:
   [ f(?x,f(?y,1)) = f(?x,?y) ]
not Overlay, check Termination...
Terminating, not WCR
Knuth & Bendix
Direct Methods: not CR

Combined result: not CR
13.trs: Success(not CR)
(1 msec.)