NO (ignored inputs)COMMENT Example 3.3.2 of \cite{Gra96thesis} Rewrite Rules: [ f(b) -> a, f(b) -> f(c), f(c) -> f(b), f(c) -> d, b -> e, c -> e', f(e) -> a, f(e') -> d ] Apply Direct Methods... Inner CPs: [ f(e) = a, f(e) = f(c), f(e') = f(b), f(e') = d ] Outer CPs: [ a = f(c), f(b) = d ] not Overlay, check Termination... unknown/not Terminating unknown Knuth & Bendix Linear unknown Development Closed unknown Strongly Closed unknown Weakly-Non-Overlapping & Non-Collapsing & Shallow unknown Upside-Parallel-Closed/Outside-Closed (inner) Parallel CPs: (not computed) unknown Toyama (Parallel CPs) Simultaneous CPs: [ f(c) = a, f(e) = a, a = f(c), f(e) = f(c), d = f(b), f(e') = f(b), f(b) = d, f(e') = d, a = f(e), f(c) = f(e), f(b) = f(e'), d = f(e') ] unknown Okui (Simultaneous CPs) unknown Strongly Depth-Preserving & Root-E-Closed/Non-E-Overlapping unknown Strongly Weight-Preserving & Root-E-Closed/Non-E-Overlapping check Locally Decreasing Diagrams by Rule Labelling... Critical Pair by Rules <4, 0> preceded by [(f,1)] joinable by a reduction of rules <[([],6)], []> Critical Pair by Rules <4, 1> preceded by [(f,1)] joinable by a reduction of rules <[], [([],2),([(f,1)],4)]> joinable by a reduction of rules <[([],6)], [([],2),([],0)]> Critical Pair by Rules <5, 2> preceded by [(f,1)] joinable by a reduction of rules <[], [([],1),([(f,1)],5)]> joinable by a reduction of rules <[([],7)], [([],1),([],3)]> Critical Pair by Rules <5, 3> preceded by [(f,1)] joinable by a reduction of rules <[([],7)], []> Critical Pair by Rules <1, 0> preceded by [] joinable by a reduction of rules <[([],2),([],0)], []> Critical Pair by Rules <3, 2> preceded by [] joinable by a reduction of rules <[], [([],1),([],3)]> unknown Diagram Decreasing check Non-Confluence... obtain 18 rules by 3 steps unfolding strenghten a and d strenghten d and a strenghten f(b) and a strenghten f(b) and d strenghten f(c) and a strenghten f(c) and d strenghten f(e) and a strenghten f(e) and d strenghten f(e') and a strenghten f(e') and d strenghten f(b) and f(c) strenghten f(b) and f(e) strenghten f(b) and f(e') strenghten f(c) and f(b) strenghten f(c) and f(e) obtain 22 candidates for checking non-joinability check by TCAP-Approximation (success) Witness for Non-Confluence: Direct Methods: not CR Final result: not CR 39.trs: Success(not CR) (18 msec.)