NO
(ignored inputs)COMMENT reduction failed
Rewrite Rules:
   [ f(a,f(a,?x)) -> b ]
Apply Direct Methods...
Inner CPs:
   [ f(a,b) = b ]
Outer CPs:
   [  ]
not Overlay, check Termination...
Terminating, not WCR
Knuth & Bendix
Direct Methods: not CR

Combined result: not CR
/tmp/filev5ibFn.trs: Success(not CR)
(0 msec.)