YES (ignored inputs)COMMENT from the collection of \cite{AT2012} Rewrite Rules: [ or(?x,T) -> T, or(?x,F) -> ?x, or(?x,?y) -> or(?y,?x) ] Apply Direct Methods... Inner CPs: [ ] Outer CPs: [ T = or(T,?x), ?x_1 = or(F,?x_1) ] Overlay, check Innermost Termination... unknown Innermost 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: [ or(T,?x) = T, or(F,?x) = ?x, T = or(T,?x), ?x = or(F,?x) ] 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 <2, 0> preceded by [] joinable by a reduction of rules <[([],2),([],0)], []> Critical Pair by Rules <2, 1> preceded by [] joinable by a reduction of rules <[([],2),([],1)], []> unknown Diagram Decreasing check Non-Confluence... obtain 13 rules by 3 steps unfolding strenghten or(?x_7,F) and ?x_7 strenghten or(?x_9,T) and T strenghten or(F,?x_2) and ?x_2 strenghten or(T,?x_2) and T strenghten or(?x_12,?y_12) and or(?y_12,?x_12) obtain 5 candidates for checking non-joinability check by TCAP-Approximation (failure) check by Root-Approximation (failure) check by Ordering(rpo), check by Tree-Automata Approximation (failure) check by Interpretation(mod2) (failure) check by Descendants-Approximation, check by Ordering(poly) (failure) unknown Non-Confluence Check relative termination: [ or(?x,T) -> T, or(?x,F) -> ?x ] [ or(?x,?y) -> or(?y,?x) ] Polynomial Interpretation: F:= (2) T:= 0 or:= (10)+(1)*x1*x1+(15)*x1*x2+(1)*x2*x2 relatively terminating unknown Huet (modulo AC) check by Reduction-Preserving Completion... STEP: 1 (parallel) S: [ or(?x,T) -> T, or(?x,F) -> ?x ] P: [ or(?x,?y) -> or(?y,?x) ] S: terminating CP(S,S): PCP_in(symP,S): CP(S,symP): --> => no --> => no check joinability condition: check modulo reachablity from T to or(T,?x): maybe not reachable check modulo reachablity from ?x to or(F,?x): maybe not reachable failed failure(Step 1) [ or(T,?x) -> T, or(F,?x) -> ?x ] Added S-Rules: [ or(T,?x) -> T, or(F,?x) -> ?x ] Added P-Rules: [ ] STEP: 2 (linear) S: [ or(?x,T) -> T, or(?x,F) -> ?x ] P: [ or(?x,?y) -> or(?y,?x) ] S: terminating CP(S,S): CP_in(symP,S): CP(S,symP): --> => no --> => no check joinability condition: check modulo reachablity from T to or(T,?x): maybe not reachable check modulo reachablity from ?x to or(F,?x): maybe not reachable failed failure(Step 2) [ or(T,?x) -> T, or(F,?x) -> ?x ] Added S-Rules: [ or(T,?x) -> T, or(F,?x) -> ?x ] Added P-Rules: [ ] STEP: 3 (relative) S: [ or(?x,T) -> T, or(?x,F) -> ?x ] P: [ or(?x,?y) -> or(?y,?x) ] Check relative termination: [ or(?x,T) -> T, or(?x,F) -> ?x ] [ or(?x,?y) -> or(?y,?x) ] Polynomial Interpretation: F:= (2) T:= 0 or:= (10)+(1)*x1*x1+(15)*x1*x2+(1)*x2*x2 relatively terminating S/P: relatively terminating check CP condition: failed failure(Step 3) STEP: 4 (parallel) S: [ or(?x,T) -> T, or(?x,F) -> ?x, or(T,?x) -> T, or(F,?x) -> ?x ] P: [ or(?x,?y) -> or(?y,?x) ] S: terminating CP(S,S): --> => yes --> => yes --> => yes --> => yes PCP_in(symP,S): CP(S,symP): --> => yes --> => yes --> => yes --> => yes S: [ or(?x,T) -> T, or(?x,F) -> ?x, or(T,?x) -> T, or(F,?x) -> ?x ] P: [ or(?x,?y) -> or(?y,?x) ] Success Reduction-Preserving Completion Direct Methods: CR Final result: CR 190.trs: Success(CR) (78 msec.)