YES
(ignored inputs)COMMENT from Example 4 of \cite{OO04}
Rewrite Rules:
   [ h(f,a,a) -> h(g,a,a),
     h(g,a,a) -> h(f,a,a),
     a -> a',
     h(?x,a',?y) -> h(?x,?y,?y),
     g -> f,
     f -> g ]
Apply Direct Methods...
Inner CPs:
   [ h(f,a',a) = h(g,a,a),
     h(f,a,a') = h(g,a,a),
     h(g,a,a) = h(g,a,a),
     h(g,a',a) = h(f,a,a),
     h(g,a,a') = h(f,a,a),
     h(f,a,a) = h(f,a,a) ]
Outer CPs:
   [  ]
not Overlay, check Termination...
unknown/not Terminating
unknown Knuth & Bendix
Left-Linear, not Right-Linear
unknown Development Closed
unknown Weakly-Non-Overlapping & Non-Collapsing & Shallow
inner CP cond (upside-parallel)
Upside-Parallel-Closed/Outside-Closed
Direct Methods: CR

Final result: CR
65.trs: Success(CR)
(8 msec.)