MAYBE
(ignored inputs)COMMENT [17] Example 4 submitted by: Takahito Aoto , Junichi Yoshida , and Yoshihito Toyama
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),
     h(?x,?y,a') -> h(?x,?y,?y) ]
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(f,a,a),
     h(g,a,a') = h(f,a,a) ]
Outer CPs:
   [ h(?x,a',a') = h(?x,a',a') ]
Left-Linear, not Right-Linear
(inner) Parallel CPs:
   [ h(f,a,a') = h(g,a,a) {},
     h(f,a',a) = h(g,a,a) {},
     h(f,a',a') = h(g,a,a) {},
     h(g,a,a') = h(f,a,a) {},
     h(g,a',a) = h(f,a,a) {},
     h(g,a',a') = h(f,a,a) {} ]
unknown Toyama (Parallel CPs)
Direct Methods: Can't judge

Combined result: Can't judge
64.trs: Failure(unknown CR)
(1 msec.)