(ignored inputs)COMMENT doi:10.4230/LIPIcs.FSCD.2016.33 [36] Example 24 submitted by: Takahito Aoto Rewrite Rules: [ +(0,?y) -> ?y, +(s(0),?y) -> s(?y), +(+(?x,?y),?z) -> +(?x,+(?y,?z)), +(?x,?y) -> +(?y,?x), s(s(?x)) -> s(?x), s(?x) -> s(s(?x)) ] Apply Direct Methods... Inner CPs: [ +(s(s(0)),?y_1) = s(?y_1), +(?y,?z_2) = +(0,+(?y,?z_2)), +(s(?y_1),?z_2) = +(s(0),+(?y_1,?z_2)), +(+(?y_3,?x_3),?z_2) = +(?x_3,+(?y_3,?z_2)), s(s(s(?x_5))) = s(?x_5), +(+(?x,+(?y,?z)),?z_1) = +(+(?x,?y),+(?z,?z_1)), s(s(?x)) = s(s(?x)) ] Outer CPs: [ ?y = +(?y,0), s(?y_1) = +(?y_1,s(0)), +(?x_2,+(?y_2,?z_2)) = +(?z_2,+(?x_2,?y_2)), s(?x_4) = s(s(s(?x_4))) ] 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: [ +(?y,0) = ?y, +(0,+(?y,?z_3)) = +(?y,?z_3), +(?y,s(s(0))) = s(?y), +(?y,s(0)) = s(?y), +(s(s(0)),?y) = s(?y), +(s(s(0)),+(?y,?z_3)) = +(s(?y),?z_3), +(s(0),+(?y,?z_3)) = +(s(?y),?z_3), +(?z,+(?x_1,+(?y_1,?y))) = +(+(?x_1,?y_1),+(?y,?z)), +(?z,?y) = +(0,+(?y,?z)), +(?z,s(?y)) = +(s(0),+(?y,?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)), +(s(?y),?z) = +(s(0),+(?y,?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), +(s(?y),+(?z,?z_1)) = +(+(s(0),+(?y,?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), s(?y) = +(?y,s(0)), +(?x_3,+(?y_3,?y)) = +(?y,+(?x_3,?y_3)), +(?x,+(?y,?z_4)) = +(+(?y,?x),?z_4), s(s(s(?x_1))) = s(s(?x_1)), s(s(s(s(?x)))) = s(?x), s(s(s(?x))) = s(?x), s(s(?x_1)) = s(s(?x_1)), s(s(?x_1)) = s(s(s(?x_1))), s(?x_5) = s(s(s(?x_5))), s(?y_3) = +(s(s(0)),?y_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 <+(s(s(0)),?y_1), s(?y_1)> by Rules <5, 1> preceded by [(+,1)] joinable by a reduction of rules <[([(+,1)],4),([],1)], []> Critical Pair <+(?y,?z_2), +(0,+(?y,?z_2))> by Rules <0, 2> preceded by [(+,1)] joinable by a reduction of rules <[], [([],0)]> Critical Pair <+(s(?y_1),?z_2), +(s(0),+(?y_1,?z_2))> 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)]> joinable by a reduction of rules <[([(+,1)],5),([],3),([(+,2)],4)], [([(+,2)],3),([],3),([],2),([(+,2)],3),([(+,2)],1)]> joinable by a reduction of rules <[([(+,1)],5),([],3),([(+,2)],4)], [([],3),([(+,1)],3),([],2),([(+,2)],3),([(+,2)],1)]> joinable by a reduction of rules <[([(+,1)],5),([],3),([(+,2)],4)], [([],3),([],2),([],3),([],2),([(+,2)],1)]> joinable by a reduction of rules <[([(+,1)],5),([(+,1),(s,1)],5),([],3),([(+,2),(s,1)],4),([(+,2)],4)], [([(+,2)],3),([],3),([],2),([(+,2)],3),([(+,2)],1)]> joinable by a reduction of rules <[([(+,1)],5),([(+,1),(s,1)],5),([],3),([(+,2),(s,1)],4),([(+,2)],4)], [([],3),([(+,1)],3),([],2),([(+,2)],3),([(+,2)],1)]> joinable by a reduction of rules <[([(+,1)],5),([(+,1),(s,1)],5),([],3),([(+,2),(s,1)],4),([(+,2)],4)], [([],3),([],2),([],3),([],2),([(+,2)],1)]> joinable by a reduction of rules <[([(+,1)],5),([(+,1),(s,1)],5),([],3),([(+,2)],4),([(+,2)],4)], [([(+,2)],3),([],3),([],2),([(+,2)],3),([(+,2)],1)]> joinable by a reduction of rules <[([(+,1)],5),([(+,1),(s,1)],5),([],3),([(+,2)],4),([(+,2)],4)], [([],3),([(+,1)],3),([],2),([(+,2)],3),([(+,2)],1)]> joinable by a reduction of rules <[([(+,1)],5),([(+,1),(s,1)],5),([],3),([(+,2)],4),([(+,2)],4)], [([],3),([],2),([],3),([],2),([(+,2)],1)]> joinable by a reduction of rules <[([(+,1)],5),([(+,1)],5),([],3),([(+,2),(s,1)],4),([(+,2)],4)], [([(+,2)],3),([],3),([],2),([(+,2)],3),([(+,2)],1)]> joinable by a reduction of rules <[([(+,1)],5),([(+,1)],5),([],3),([(+,2),(s,1)],4),([(+,2)],4)], [([],3),([(+,1)],3),([],2),([(+,2)],3),([(+,2)],1)]> joinable by a reduction of rules <[([(+,1)],5),([(+,1)],5),([],3),([(+,2),(s,1)],4),([(+,2)],4)], [([],3),([],2),([],3),([],2),([(+,2)],1)]> joinable by a reduction of rules <[([(+,1)],5),([(+,1)],5),([],3),([(+,2)],4),([(+,2)],4)], [([(+,2)],3),([],3),([],2),([(+,2)],3),([(+,2)],1)]> joinable by a reduction of rules <[([(+,1)],5),([(+,1)],5),([],3),([(+,2)],4),([(+,2)],4)], [([],3),([(+,1)],3),([],2),([(+,2)],3),([(+,2)],1)]> joinable by a reduction of rules <[([(+,1)],5),([(+,1)],5),([],3),([(+,2)],4),([(+,2)],4)], [([],3),([],2),([],3),([],2),([(+,2)],1)]> Critical Pair <+(+(?y_3,?x_3),?z_2), +(?x_3,+(?y_3,?z_2))> 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 by Rules <5, 4> preceded by [(s,1)] joinable by a reduction of rules <[([(s,1)],4)], [([],5)]> joinable by a reduction of rules <[([],4)], [([],5)]> 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 by Rules <4, 4> preceded by [(s,1)] joinable by a reduction of rules <[], []> Critical Pair <+(?y_3,0), ?y_3> by Rules <3, 0> preceded by [] joinable by a reduction of rules <[([],3),([],0)], []> Critical Pair <+(?y_3,s(0)), s(?y_3)> by Rules <3, 1> preceded by [] joinable by a reduction of rules <[([],3),([],1)], []> Critical Pair <+(?y_3,+(?x_2,?y_2)), +(?x_2,+(?y_2,?y_3))> by Rules <3, 2> preceded by [] joinable by a reduction of rules <[([],3),([],2)], []> Critical Pair by Rules <5, 4> preceded by [] joinable by a reduction of rules <[([(s,1)],4)], [([],5)]> joinable by a reduction of rules <[([],4)], [([],5)]> unknown Diagram Decreasing check Non-Confluence... obtain 8 rules by 3 steps unfolding obtain 100 candidates for checking non-joinability check by TCAP-Approximation (failure) check by Ordering(rpo), check by Tree-Automata Approximation (success) where F = {(+,2),(0,0),(s,1),(c_1,0),(c_2,0)} Q = {q_0,q_1,q_{+(*,*)},q_{c_1},q_{c_2},q_{s(c_1)},q_{*},q_{+(c_1,c_2)}} Qf = {q_0,q_1} Delta = [ +(q_{+(*,*)},q_{+(*,*)}) -> q_{+(*,*)}, +(q_{+(*,*)},q_{*}) -> q_{+(*,*)}, +(q_{c_1},q_{c_2}) -> q_{+(c_1,c_2)}, +(q_{c_2},q_{c_1}) -> q_{+(c_1,c_2)}, +(q_{c_2},q_{s(c_1)}) -> q_1, +(q_{s(c_1)},q_{c_2}) -> q_1, +(q_{*},q_{+(*,*)}) -> q_{+(*,*)}, +(q_{*},q_{*}) -> q_{+(*,*)}, +(q_{*},q_{*}) -> q_{*}, 0 -> q_{+(*,*)}, 0 -> q_{*}, s(q_0) -> q_0, s(q_{+(*,*)}) -> q_{+(*,*)}, s(q_{c_1}) -> q_{s(c_1)}, s(q_{s(c_1)}) -> q_{s(c_1)}, s(q_{*}) -> q_{+(*,*)}, s(q_{*}) -> q_{*}, s(q_{+(c_1,c_2)}) -> q_0, c_1 -> q_{+(*,*)}, c_1 -> q_{c_1}, c_1 -> q_{*}, c_2 -> q_{+(*,*)}, c_2 -> q_{c_2}, c_2 -> q_{*} ] Witness for Non-Confluence: Direct Methods: not CR Combined result: not CR 574.trs: Success(not CR) NO (453 msec.)