YES (ignored inputs)COMMENT doi:10.1145/322217.322230 [12] p. 814 , attributed to Levy submitted by: Takahito Aoto , Junichi Yoshida , and Yoshihito Toyama Input: [ 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) ] Make it flat: [ 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) ] Time: 0.000 [s] Make it Complete (R^): [ G(B,B') = F(A,A), G(B',B) = F(A,A), F(A,A') = G(B,B), F(A',A) = G(B,B), F(A,A) = G(B',B'), G(B,B') = F(A',A'), G(B',B) = F(A',A'), F(A',A) = G(B',B'), G(B',B) = F(A,A'), F(A',A) = G(B',B), G(B,B') = F(A',A), G(B,B') = F(A,A'), F(A,A') = G(B',B'), F(A',A') = G(B',B'), G(B,B) = F(A',A'), F(A,A) = G(B,B), F(?x,A) = F(?x,?x), F(A,?x) = F(?x,?x), F(?x,A) = F(A',?x), F(?x,A) = F(?x,A'), F(?x,A) = F(A,?x), F(A,A') = F(A',A'), F(A,?x) = F(A',?x), F(A,A) = F(A',A'), F(A,A) = F(A,A'), F(A,A) = F(A',A), F(A,A') = F(A',A), F(A',A') = F(A',A), F(A,?x) = F(?x,A'), A = A', F(A',?x) = F(?x,A'), F(A',?x) = F(?x,?x), F(?x,A') = F(?x,?x), G(?x,B) = G(?x,?x), G(B,?x) = G(?x,?x), G(?x,B) = G(B',?x), G(?x,B) = G(?x,B'), G(?x,B) = G(B,?x), G(B,B') = G(B',B'), G(B,?x) = G(B',?x), G(B,B) = G(B',B'), G(B,B) = G(B,B'), G(B,B) = G(B',B), G(B,B') = G(B',B), G(B',B') = G(B',B), G(B,?x) = G(?x,B'), B = B', G(B',?x) = G(?x,B'), G(B',?x) = G(?x,?x), G(?x,B') = G(?x,?x) ] Time: 0.054 [s] CPNF: [ A … A', B … B' ] Time: 0.000 [s] Now checking all the pairs in CW... Time to check pairs: 0.000 [s] The TRS has Uniqueness of Normal Forms. Total Time: 0.055 [s] problems/49.trs: Success(UNC) real 0.07 user 0.06 sys 0.01