MAYBE (ignored inputs)COMMENT from the collection of \cite{AT2012} Rewrite Rules: [ +(0,?x) -> ?x, +(1,-(1)) -> 0, +(+(?x,?y),?z) -> +(?x,+(?y,?z)), +(?x,?y) -> +(?y,?x) ] Apply Direct Methods... Inner CPs: [ +(?x,?z_1) = +(0,+(?x,?z_1)), +(0,?z_1) = +(1,+(-(1),?z_1)), +(+(?y_2,?x_2),?z_1) = +(?x_2,+(?y_2,?z_1)), +(+(?x,+(?y,?z)),?z_1) = +(+(?x,?y),+(?z,?z_1)) ] Outer CPs: [ ?x = +(?x,0), 0 = +(-(1),1), +(?x_1,+(?y_1,?z_1)) = +(?z_1,+(?x_1,?y_1)) ] 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: [ +(?x,0) = ?x, +(0,+(?x,?z_2)) = +(?x,?z_2), +(-(1),1) = 0, +(1,+(-(1),?z_1)) = +(0,?z_1), +(?z,+(?x_1,+(?y_1,?y))) = +(+(?x_1,?y_1),+(?y,?z)), +(?z,?y) = +(0,+(?y,?z)), +(?z,0) = +(1,+(-(1),?z)), +(?z,+(?y,?x)) = +(?x,+(?y,?z)), +(?z,+(?x,?y)) = +(?x,+(?y,?z)), +(+(?x_1,+(?y_1,?y)),?z) = +(+(?x_1,?y_1),+(?y,?z)), +(?y,?z) = +(0,+(?y,?z)), +(0,?z) = +(1,+(-(1),?z)), +(+(?y,?x),?z) = +(?x,+(?y,?z)), +(+(?x_2,+(?y_2,?y)),+(?z,?z_1)) = +(+(+(?x_2,?y_2),+(?y,?z)),?z_1), +(?y,+(?z,?z_1)) = +(+(0,+(?y,?z)),?z_1), +(0,+(?z,?z_1)) = +(+(1,+(-(1),?z)),?z_1), +(+(?y,?x),+(?z,?z_1)) = +(+(?x,+(?y,?z)),?z_1), +(+(?x,?y),+(?z,?z_1)) = +(+(?x,+(?y,?z)),?z_1), ?y = +(?y,0), 0 = +(-(1),1), +(?x_2,+(?y_2,?y)) = +(?y,+(?x_2,?y_2)), +(?x,+(?y,?z_3)) = +(+(?y,?x),?z_3) ] 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 <+(?x,?z_1), +(0,+(?x,?z_1))> by Rules <0, 2> preceded by [(+,1)] joinable by a reduction of rules <[], [([],0)]> Critical Pair <+(0,?z_1), +(1,+(-(1),?z_1))> by Rules <1, 2> preceded by [(+,1)] joinable by a reduction of rules <[([],3)], [([(+,2)],3),([],3),([],2),([(+,2)],3),([(+,2)],1)]> joinable by a reduction of rules <[([],3)], [([],3),([(+,1)],3),([],2),([(+,2)],3),([(+,2)],1)]> joinable by a reduction of rules <[([],3)], [([],3),([],2),([],3),([],2),([(+,2)],1)]> Critical Pair <+(+(?y_2,?x_2),?z_1), +(?x_2,+(?y_2,?z_1))> by Rules <3, 2> preceded by [(+,1)] joinable by a reduction of rules <[([(+,1)],3),([],2)], []> joinable by a reduction of rules <[([],2),([(+,2)],3)], [([],3),([],2)]> Critical Pair <+(+(?x,+(?y,?z)),?z_1), +(+(?x,?y),+(?z,?z_1))> by Rules <2, 2> preceded by [(+,1)] joinable by a reduction of rules <[([],2),([(+,2)],2)], [([],2)]> Critical Pair <+(?y_2,0), ?y_2> by Rules <3, 0> preceded by [] joinable by a reduction of rules <[([],3),([],0)], []> Critical Pair <+(-(1),1), 0> by Rules <3, 1> preceded by [] joinable by a reduction of rules <[([],3),([],1)], []> Critical Pair <+(?y_2,+(?x_1,?y_1)), +(?x_1,+(?y_1,?y_2))> by Rules <3, 2> preceded by [] joinable by a reduction of rules <[([],3),([],2)], []> unknown Diagram Decreasing check Non-Confluence... obtain 14 rules by 3 steps unfolding strenghten +(?x_5,0) and ?x_5 strenghten +(0,?x_3) and ?x_3 strenghten +(-(1),1) and 0 strenghten +(1,-(1)) and 0 strenghten +(?x_8,?y_8) and +(?y_8,?x_8) strenghten +(?x_1,+(?y_1,0)) and +(?x_1,?y_1) strenghten +(?x_3,+(0,?z_1)) and +(?x_3,?z_1) strenghten +(0,+(?x,?z_1)) and +(?x,?z_1) strenghten +(-(1),+(1,?z_1)) and +(0,?z_1) strenghten +(1,+(-(1),?z_1)) and +(0,?z_1) strenghten +(?x_1,+(?y_1,?x_9)) and +(?x_9,+(?x_1,?y_1)) strenghten +(?x_1,+(?y_1,?x_10)) and +(+(?x_1,?y_1),?x_10) strenghten +(?x_2,+(?y_2,?z_1)) and +(+(?y_2,?x_2),?z_1) strenghten +(+(?x,?y),+(?z,?z_1)) and +(+(?x,+(?y,?z)),?z_1) obtain 100 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: [ +(0,?x) -> ?x, +(1,-(1)) -> 0 ] [ +(+(?x,?y),?z) -> +(?x,+(?y,?z)), +(?x,?y) -> +(?y,?x) ] Polynomial Interpretation: +:= (1)*x1+(1)*x2 -:= (13)+(2)*x1*x1 0:= 0 1:= 0 retract +(1,-(1)) -> 0 Polynomial Interpretation: +:= (1)*x1+(1)*x2 -:= (8)+(2)*x1*x1 0:= (8) 1:= 0 relatively terminating unknown Huet (modulo AC) check by Reduction-Preserving Completion... STEP: 1 (parallel) S: [ +(0,?x) -> ?x, +(1,-(1)) -> 0 ] P: [ +(+(?x,?y),?z) -> +(?x,+(?y,?z)), +(?x,?y) -> +(?y,?x) ] S: terminating CP(S,S): PCP_in(symP,S): CP(S,symP): <+(?x,?z_1), +(0,+(?x,?z_1))> --> <+(?x,?z_1), +(?x,?z_1)> => yes <+(?y_1,?z_1), +(+(0,?y_1),?z_1)> --> <+(?y_1,?z_1), +(?y_1,?z_1)> => yes <+(?x_1,?x), +(+(?x_1,0),?x)> --> <+(?x_1,?x), +(+(?x_1,0),?x)> => no --> => no <+(0,?z), +(1,+(-(1),?z))> --> => no <+(?x,0), +(+(?x,1),-(1))> --> <+(?x,0), +(+(?x,1),-(1))> => no <0, +(-(1),1)> --> <0, +(-(1),1)> => no check joinability condition: check modulo reachablity from +(?x_1,?x) to +(+(?x_1,0),?x): maybe not reachable check modulo reachablity from ?x to +(?x,0): maybe not reachable check modulo reachablity from ?z to +(1,+(-(1),?z)): maybe not reachable check modulo reachablity from +(?x,0) to +(+(?x,1),-(1)): maybe not reachable check modulo reachablity from 0 to +(-(1),1): maybe not reachable failed failure(Step 1) [ +(?x,0) -> ?x, +(-(1),1) -> 0 ] Added S-Rules: [ +(?x,0) -> ?x, +(-(1),1) -> 0 ] Added P-Rules: [ ] STEP: 2 (linear) S: [ +(0,?x) -> ?x, +(1,-(1)) -> 0 ] P: [ +(+(?x,?y),?z) -> +(?x,+(?y,?z)), +(?x,?y) -> +(?y,?x) ] S: terminating CP(S,S): CP_in(symP,S): CP(S,symP): <+(?x,?z_1), +(0,+(?x,?z_1))> --> <+(?x,?z_1), +(?x,?z_1)> => yes <+(?y_1,?z_1), +(+(0,?y_1),?z_1)> --> <+(?y_1,?z_1), +(?y_1,?z_1)> => yes <+(?x_1,?x), +(+(?x_1,0),?x)> --> <+(?x_1,?x), +(+(?x_1,0),?x)> => no --> => no <+(0,?z), +(1,+(-(1),?z))> --> => no <+(?x,0), +(+(?x,1),-(1))> --> <+(?x,0), +(+(?x,1),-(1))> => no <0, +(-(1),1)> --> <0, +(-(1),1)> => no check joinability condition: check modulo reachablity from +(?x_1,?x) to +(+(?x_1,0),?x): maybe not reachable check modulo reachablity from ?x to +(?x,0): maybe not reachable check modulo reachablity from ?z to +(1,+(-(1),?z)): maybe not reachable check modulo reachablity from +(?x,0) to +(+(?x,1),-(1)): maybe not reachable check modulo reachablity from 0 to +(-(1),1): maybe not reachable failed failure(Step 2) [ +(?x,0) -> ?x, +(-(1),1) -> 0 ] Added S-Rules: [ +(?x,0) -> ?x, +(-(1),1) -> 0 ] Added P-Rules: [ ] STEP: 3 (relative) S: [ +(0,?x) -> ?x, +(1,-(1)) -> 0 ] P: [ +(+(?x,?y),?z) -> +(?x,+(?y,?z)), +(?x,?y) -> +(?y,?x) ] Check relative termination: [ +(0,?x) -> ?x, +(1,-(1)) -> 0 ] [ +(+(?x,?y),?z) -> +(?x,+(?y,?z)), +(?x,?y) -> +(?y,?x) ] Polynomial Interpretation: +:= (1)*x1+(1)*x2 -:= (13)+(2)*x1*x1 0:= 0 1:= 0 retract +(1,-(1)) -> 0 Polynomial Interpretation: +:= (1)*x1+(1)*x2 -:= (8)+(2)*x1*x1 0:= (8) 1:= 0 relatively terminating S/P: relatively terminating check CP condition: failed failure(Step 3) STEP: 4 (parallel) S: [ +(0,?x) -> ?x, +(1,-(1)) -> 0, +(?x,0) -> ?x, +(-(1),1) -> 0 ] P: [ +(+(?x,?y),?z) -> +(?x,+(?y,?z)), +(?x,?y) -> +(?y,?x) ] S: terminating CP(S,S): <0, 0> --> <0, 0> => yes PCP_in(symP,S): CP(S,symP): <+(?x,?z_1), +(0,+(?x,?z_1))> --> <+(?x,?z_1), +(?x,?z_1)> => yes <+(?y_1,?z_1), +(+(0,?y_1),?z_1)> --> <+(?y_1,?z_1), +(?y_1,?z_1)> => yes <+(?x_1,?x), +(+(?x_1,0),?x)> --> <+(?x_1,?x), +(?x_1,?x)> => yes --> => yes <+(0,?z), +(1,+(-(1),?z))> --> => no <+(?x,0), +(+(?x,1),-(1))> --> => no <0, +(-(1),1)> --> <0, 0> => yes <+(?x_1,?y_1), +(?x_1,+(?y_1,0))> --> <+(?x_1,?y_1), +(?x_1,?y_1)> => yes <+(?x,?z_1), +(?x,+(0,?z_1))> --> <+(?x,?z_1), +(?x,?z_1)> => yes <+(?x_1,?x), +(+(?x_1,?x),0)> --> <+(?x_1,?x), +(?x_1,?x)> => yes --> => yes <+(0,?z), +(-(1),+(1,?z))> --> => no <+(?x,0), +(+(?x,-(1)),1)> --> => no <0, +(1,-(1))> --> <0, 0> => yes check joinability condition: check modulo reachablity from ?z to +(1,+(-(1),?z)): maybe not reachable check modulo reachablity from ?x to +(+(?x,1),-(1)): maybe not reachable check modulo reachablity from ?z to +(-(1),+(1,?z)): maybe not reachable check modulo reachablity from ?x to +(+(?x,-(1)),1): maybe not reachable failed failure(Step 4) [ ] Added S-Rules: [ ] Added P-Rules: [ ] STEP: 5 (linear) S: [ +(0,?x) -> ?x, +(1,-(1)) -> 0, +(?x,0) -> ?x, +(-(1),1) -> 0 ] P: [ +(+(?x,?y),?z) -> +(?x,+(?y,?z)), +(?x,?y) -> +(?y,?x) ] S: terminating CP(S,S): <0, 0> --> <0, 0> => yes CP_in(symP,S): CP(S,symP): <+(?x,?z_1), +(0,+(?x,?z_1))> --> <+(?x,?z_1), +(?x,?z_1)> => yes <+(?y_1,?z_1), +(+(0,?y_1),?z_1)> --> <+(?y_1,?z_1), +(?y_1,?z_1)> => yes <+(?x_1,?x), +(+(?x_1,0),?x)> --> <+(?x_1,?x), +(?x_1,?x)> => yes --> => yes <+(0,?z), +(1,+(-(1),?z))> --> => no <+(?x,0), +(+(?x,1),-(1))> --> => no <0, +(-(1),1)> --> <0, 0> => yes <+(?x_1,?y_1), +(?x_1,+(?y_1,0))> --> <+(?x_1,?y_1), +(?x_1,?y_1)> => yes <+(?x,?z_1), +(?x,+(0,?z_1))> --> <+(?x,?z_1), +(?x,?z_1)> => yes <+(?x_1,?x), +(+(?x_1,?x),0)> --> <+(?x_1,?x), +(?x_1,?x)> => yes --> => yes <+(0,?z), +(-(1),+(1,?z))> --> => no <+(?x,0), +(+(?x,-(1)),1)> --> => no <0, +(1,-(1))> --> <0, 0> => yes check joinability condition: check modulo reachablity from ?z to +(1,+(-(1),?z)): maybe not reachable check modulo reachablity from ?x to +(+(?x,1),-(1)): maybe not reachable check modulo reachablity from ?z to +(-(1),+(1,?z)): maybe not reachable check modulo reachablity from ?x to +(+(?x,-(1)),1): maybe not reachable failed failure(Step 5) [ ] Added S-Rules: [ ] Added P-Rules: [ ] STEP: 6 (relative) S: [ +(0,?x) -> ?x, +(1,-(1)) -> 0, +(?x,0) -> ?x, +(-(1),1) -> 0 ] P: [ +(+(?x,?y),?z) -> +(?x,+(?y,?z)), +(?x,?y) -> +(?y,?x) ] Check relative termination: [ +(0,?x) -> ?x, +(1,-(1)) -> 0, +(?x,0) -> ?x, +(-(1),1) -> 0 ] [ +(+(?x,?y),?z) -> +(?x,+(?y,?z)), +(?x,?y) -> +(?y,?x) ] Polynomial Interpretation: +:= (1)*x1+(1)*x2 -:= (13)+(2)*x1*x1 0:= 0 1:= 0 retract +(1,-(1)) -> 0 retract +(-(1),1) -> 0 Polynomial Interpretation: +:= (1)*x1+(1)*x2 -:= (12)+(2)*x1*x1 0:= (8) 1:= 0 relatively terminating S/P: relatively terminating check CP condition: failed failure(Step 6) failure(no possibility remains) unknown Reduction-Preserving Completion Direct Methods: Can't judge Try Persistent Decomposition for... [ +(0,?x) -> ?x, +(1,-(1)) -> 0, +(+(?x,?y),?z) -> +(?x,+(?y,?z)), +(?x,?y) -> +(?y,?x) ] Sort Assignment: + : 14*14=>14 - : 14=>14 0 : =>14 1 : =>14 maximal types: {14} Persistent Decomposition failed: Can't judge Try Layer Preserving Decomposition for... [ +(0,?x) -> ?x, +(1,-(1)) -> 0, +(+(?x,?y),?z) -> +(?x,+(?y,?z)), +(?x,?y) -> +(?y,?x) ] Layer Preserving Decomposition failed: Can't judge Try Commutative Decomposition for... [ +(0,?x) -> ?x, +(1,-(1)) -> 0, +(+(?x,?y),?z) -> +(?x,+(?y,?z)), +(?x,?y) -> +(?y,?x) ] Outside Critical Pair: <+(?y_2,0), ?y_2> by Rules <3, 0> develop reducts from lhs term... <{3}, +(0,?y_2)> <{}, +(?y_2,0)> develop reducts from rhs term... <{}, ?y_2> Outside Critical Pair: <+(-(1),1), 0> by Rules <3, 1> develop reducts from lhs term... <{3}, +(1,-(1))> <{}, +(-(1),1)> develop reducts from rhs term... <{}, 0> Outside Critical Pair: <+(?y_2,+(?x_1,?y_1)), +(?x_1,+(?y_1,?y_2))> by Rules <3, 2> develop reducts from lhs term... <{3}, +(+(?y_1,?x_1),?y_2)> <{3}, +(+(?x_1,?y_1),?y_2)> <{3}, +(?y_2,+(?y_1,?x_1))> <{}, +(?y_2,+(?x_1,?y_1))> develop reducts from rhs term... <{3}, +(+(?y_2,?y_1),?x_1)> <{3}, +(+(?y_1,?y_2),?x_1)> <{3}, +(?x_1,+(?y_2,?y_1))> <{}, +(?x_1,+(?y_1,?y_2))> Inside Critical Pair: <+(?x,?z_1), +(0,+(?x,?z_1))> by Rules <0, 2> develop reducts from lhs term... <{3}, +(?z_1,?x)> <{}, +(?x,?z_1)> develop reducts from rhs term... <{3}, +(+(?z_1,?x),0)> <{3}, +(+(?x,?z_1),0)> <{0,3}, +(?z_1,?x)> <{0}, +(?x,?z_1)> <{3}, +(0,+(?z_1,?x))> <{}, +(0,+(?x,?z_1))> Inside Critical Pair: <+(0,?z_1), +(1,+(-(1),?z_1))> by Rules <1, 2> develop reducts from lhs term... <{3}, +(?z_1,0)> <{0}, ?z_1> <{}, +(0,?z_1)> develop reducts from rhs term... <{3}, +(+(?z_1,-(1)),1)> <{3}, +(+(-(1),?z_1),1)> <{3}, +(1,+(?z_1,-(1)))> <{}, +(1,+(-(1),?z_1))> Inside Critical Pair: <+(+(?y_2,?x_2),?z_1), +(?x_2,+(?y_2,?z_1))> by Rules <3, 2> develop reducts from lhs term... <{3}, +(?z_1,+(?x_2,?y_2))> <{3}, +(?z_1,+(?y_2,?x_2))> <{2}, +(?y_2,+(?x_2,?z_1))> <{3}, +(+(?x_2,?y_2),?z_1)> <{}, +(+(?y_2,?x_2),?z_1)> develop reducts from rhs term... <{3}, +(+(?z_1,?y_2),?x_2)> <{3}, +(+(?y_2,?z_1),?x_2)> <{3}, +(?x_2,+(?z_1,?y_2))> <{}, +(?x_2,+(?y_2,?z_1))> Commutative Decomposition failed: Can't judge No further decomposition possible Final result: Can't judge 206.trs: Failure(unknown) (3119 msec.)