YES
(ignored inputs)COMMENT generated by FORT "UN & ~UNC" submitted by: Franziska Rapp
Rewrite Rules:
   [ f(a,f(?x,a)) -> f(a,f(f(a,a),a)) ]
Apply Direct Methods...
Inner CPs:
   [  ]
Outer CPs:
   [  ]
Overlay, check Innermost Termination...
unknown Innermost Terminating
unknown Knuth & Bendix
Linear
Development Closed
Direct Methods: CR

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