MAYBE (ignored inputs)COMMENT doi:10.1145/322217.322230 [12] p. 814 , attributed to Levy submitted by: Takahito Aoto , Junichi Yoshida , and Yoshihito Toyama input TRS: [ F(A,A) -> G(B,B), A -> A', F(A',?x) -> F(?x,?x), F(?x,A') -> F(?x,?x), G(B,B) -> F(A,A), B -> B', G(B',?x) -> G(?x,?x), G(?x,B') -> G(?x,?x) ] TRS: [ F(A,A) -> G(B,B), A -> A', F(A',?x) -> F(?x,?x), F(?x,A') -> F(?x,?x), G(B,B) -> F(A,A), B -> B', G(B',?x) -> G(?x,?x), G(?x,B') -> G(?x,?x) ] unknown Right-Reducible problems/49.trs: Failure(unknown UNC) (4 msec.)