NO Rewrite Rules: [ eq(?x,?x) -> true, eq(0,s(?y)) -> false, eq(s(?x),0) -> false, not(true) -> false, not(false) -> true, neq(?x,?y) -> not(eq(?x,?y)), neq(?x,s(?x)) -> true ] Apply Direct Methods... Inner CPs: [ ] Outer CPs: [ not(eq(?x_3,s(?x_3))) = true ] Overlay, check Innermost Termination... Innermost Terminating (hence Terminating), not WCR Knuth & Bendix Direct Methods: not CR Final result: not CR new/eq2.trs: Success(not CR) (0 msec.)