YES We show the termination of the TRS R: minus(x,|0|()) -> x minus(s(x),s(y)) -> minus(x,y) quot(|0|(),s(y)) -> |0|() quot(s(x),s(y)) -> s(quot(minus(x,y),s(y))) minus(minus(x,y),z) -> minus(x,plus(y,z)) plus(s(x),s(y)) -> s(s(plus(if(gt(x,y),x,y),if(not(gt(x,y)),id(x),id(y))))) plus(s(x),x) -> plus(if(gt(x,x),id(x),id(x)),s(x)) plus(zero(),y) -> y plus(id(x),s(y)) -> s(plus(x,if(gt(s(y),y),y,s(y)))) id(x) -> x if(true(),x,y) -> x if(false(),x,y) -> y not(x) -> if(x,false(),true()) gt(s(x),zero()) -> true() gt(zero(),y) -> false() gt(s(x),s(y)) -> gt(x,y) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: minus#(s(x),s(y)) -> minus#(x,y) p2: quot#(s(x),s(y)) -> quot#(minus(x,y),s(y)) p3: quot#(s(x),s(y)) -> minus#(x,y) p4: minus#(minus(x,y),z) -> minus#(x,plus(y,z)) p5: minus#(minus(x,y),z) -> plus#(y,z) p6: plus#(s(x),s(y)) -> plus#(if(gt(x,y),x,y),if(not(gt(x,y)),id(x),id(y))) p7: plus#(s(x),s(y)) -> if#(gt(x,y),x,y) p8: plus#(s(x),s(y)) -> gt#(x,y) p9: plus#(s(x),s(y)) -> if#(not(gt(x,y)),id(x),id(y)) p10: plus#(s(x),s(y)) -> not#(gt(x,y)) p11: plus#(s(x),s(y)) -> id#(x) p12: plus#(s(x),s(y)) -> id#(y) p13: plus#(s(x),x) -> plus#(if(gt(x,x),id(x),id(x)),s(x)) p14: plus#(s(x),x) -> if#(gt(x,x),id(x),id(x)) p15: plus#(s(x),x) -> gt#(x,x) p16: plus#(s(x),x) -> id#(x) p17: plus#(id(x),s(y)) -> plus#(x,if(gt(s(y),y),y,s(y))) p18: plus#(id(x),s(y)) -> if#(gt(s(y),y),y,s(y)) p19: plus#(id(x),s(y)) -> gt#(s(y),y) p20: not#(x) -> if#(x,false(),true()) p21: gt#(s(x),s(y)) -> gt#(x,y) and R consists of: r1: minus(x,|0|()) -> x r2: minus(s(x),s(y)) -> minus(x,y) r3: quot(|0|(),s(y)) -> |0|() r4: quot(s(x),s(y)) -> s(quot(minus(x,y),s(y))) r5: minus(minus(x,y),z) -> minus(x,plus(y,z)) r6: plus(s(x),s(y)) -> s(s(plus(if(gt(x,y),x,y),if(not(gt(x,y)),id(x),id(y))))) r7: plus(s(x),x) -> plus(if(gt(x,x),id(x),id(x)),s(x)) r8: plus(zero(),y) -> y r9: plus(id(x),s(y)) -> s(plus(x,if(gt(s(y),y),y,s(y)))) r10: id(x) -> x r11: if(true(),x,y) -> x r12: if(false(),x,y) -> y r13: not(x) -> if(x,false(),true()) r14: gt(s(x),zero()) -> true() r15: gt(zero(),y) -> false() r16: gt(s(x),s(y)) -> gt(x,y) The estimated dependency graph contains the following SCCs: {p2} {p1, p4} {p6, p13, p17} {p21} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: quot#(s(x),s(y)) -> quot#(minus(x,y),s(y)) and R consists of: r1: minus(x,|0|()) -> x r2: minus(s(x),s(y)) -> minus(x,y) r3: quot(|0|(),s(y)) -> |0|() r4: quot(s(x),s(y)) -> s(quot(minus(x,y),s(y))) r5: minus(minus(x,y),z) -> minus(x,plus(y,z)) r6: plus(s(x),s(y)) -> s(s(plus(if(gt(x,y),x,y),if(not(gt(x,y)),id(x),id(y))))) r7: plus(s(x),x) -> plus(if(gt(x,x),id(x),id(x)),s(x)) r8: plus(zero(),y) -> y r9: plus(id(x),s(y)) -> s(plus(x,if(gt(s(y),y),y,s(y)))) r10: id(x) -> x r11: if(true(),x,y) -> x r12: if(false(),x,y) -> y r13: not(x) -> if(x,false(),true()) r14: gt(s(x),zero()) -> true() r15: gt(zero(),y) -> false() r16: gt(s(x),s(y)) -> gt(x,y) The set of usable rules consists of r1, r2, r5, r12 Take the reduction pair: generalized weighted path order (>=MG, >G) base order 1: trivial reduction triple (T x T, T x T, Φ) base order 2: lexicographic combination of reduction triples: 1. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: quot#_A(x1,x2) = max{0, x2 - 8} s_A(x1) = x1 + 9 minus_A(x1,x2) = max{5, x1 + 3} |0|_A = 13 plus_A(x1,x2) = max{18, x1 - 105} if_A(x1,x2,x3) = max{x1 - 1, x2 + 38, x3 + 29} false_A = 99 quot#!_A(x1,x2) = max{54, x2 + 45} s!_A(x1) = x1 + 54 minus!_A(x1,x2) = 53 |0|!_A = 5 plus!_A(x1,x2) = max{1, x1 - 21} if!_A(x1,x2,x3) = max{3, x1 - 25} false!_A = 53 2. marked-algebra reduction triple (>=A, >=A!, >A!): matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: quot#_A(x1,x2) = 0 s_A(x1) = x1 + 2 minus_A(x1,x2) = x1 + 1 |0|_A() = 2 plus_A(x1,x2) = 1 if_A(x1,x2,x3) = x3 + 1 false_A() = 2 quot#!_A(x1,x2) = x2 + 1 s!_A(x1) = 7 minus!_A(x1,x2) = 2 |0|!_A() = 0 plus!_A(x1,x2) = 1 if!_A(x1,x2,x3) = 0 false!_A() = 3 partial status: pi(quot#) = [1] pi(s) = [1] pi(minus) = [1] pi(|0|) = [] pi(plus) = [1] pi(if) = [2, 3] pi(false) = [] The following rules are removed: p1 Then no dependency pair remains. -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: minus#(s(x),s(y)) -> minus#(x,y) p2: minus#(minus(x,y),z) -> minus#(x,plus(y,z)) and R consists of: r1: minus(x,|0|()) -> x r2: minus(s(x),s(y)) -> minus(x,y) r3: quot(|0|(),s(y)) -> |0|() r4: quot(s(x),s(y)) -> s(quot(minus(x,y),s(y))) r5: minus(minus(x,y),z) -> minus(x,plus(y,z)) r6: plus(s(x),s(y)) -> s(s(plus(if(gt(x,y),x,y),if(not(gt(x,y)),id(x),id(y))))) r7: plus(s(x),x) -> plus(if(gt(x,x),id(x),id(x)),s(x)) r8: plus(zero(),y) -> y r9: plus(id(x),s(y)) -> s(plus(x,if(gt(s(y),y),y,s(y)))) r10: id(x) -> x r11: if(true(),x,y) -> x r12: if(false(),x,y) -> y r13: not(x) -> if(x,false(),true()) r14: gt(s(x),zero()) -> true() r15: gt(zero(),y) -> false() r16: gt(s(x),s(y)) -> gt(x,y) The set of usable rules consists of r1 Take the reduction pair: generalized weighted path order (>=MG, >G) base order 1: trivial reduction triple (T x T, T x T, Φ) base order 2: lexicographic combination of reduction triples: 1. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: minus#_A(x1,x2) = max{0, x1 - 17} s_A(x1) = max{19, x1 + 16} minus_A(x1,x2) = max{x1 + 15, x2 - 23} plus_A(x1,x2) = max{22, x1 + 16, x2 + 16} |0|_A = 2 minus#!_A(x1,x2) = max{0, x1 - 18} s!_A(x1) = max{0, x1 - 27} minus!_A(x1,x2) = max{0, x1 - 17, x2 - 20} plus!_A(x1,x2) = max{0, x1 - 16} |0|!_A = 2 2. marked-algebra reduction triple (>=A, >=A!, >A!): matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: minus#_A(x1,x2) = x1 s_A(x1) = x1 + 5 minus_A(x1,x2) = x1 + x2 + 1 plus_A(x1,x2) = 2 |0|_A() = 2 minus#!_A(x1,x2) = x1 + 5 s!_A(x1) = 4 minus!_A(x1,x2) = x1 + 6 plus!_A(x1,x2) = x1 + 2 |0|!_A() = 6 partial status: pi(minus#) = [] pi(s) = [1] pi(minus) = [1, 2] pi(plus) = [2] pi(|0|) = [] The following rules are removed: p1, p2 Then no dependency pair remains. -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: plus#(s(x),s(y)) -> plus#(if(gt(x,y),x,y),if(not(gt(x,y)),id(x),id(y))) p2: plus#(id(x),s(y)) -> plus#(x,if(gt(s(y),y),y,s(y))) p3: plus#(s(x),x) -> plus#(if(gt(x,x),id(x),id(x)),s(x)) and R consists of: r1: minus(x,|0|()) -> x r2: minus(s(x),s(y)) -> minus(x,y) r3: quot(|0|(),s(y)) -> |0|() r4: quot(s(x),s(y)) -> s(quot(minus(x,y),s(y))) r5: minus(minus(x,y),z) -> minus(x,plus(y,z)) r6: plus(s(x),s(y)) -> s(s(plus(if(gt(x,y),x,y),if(not(gt(x,y)),id(x),id(y))))) r7: plus(s(x),x) -> plus(if(gt(x,x),id(x),id(x)),s(x)) r8: plus(zero(),y) -> y r9: plus(id(x),s(y)) -> s(plus(x,if(gt(s(y),y),y,s(y)))) r10: id(x) -> x r11: if(true(),x,y) -> x r12: if(false(),x,y) -> y r13: not(x) -> if(x,false(),true()) r14: gt(s(x),zero()) -> true() r15: gt(zero(),y) -> false() r16: gt(s(x),s(y)) -> gt(x,y) The set of usable rules consists of r10, r11, r12, r13, r14, r15, r16 Take the reduction pair: generalized weighted path order (>=MG, >G) base order 1: trivial reduction triple (T x T, T x T, Φ) base order 2: lexicographic combination of reduction triples: 1. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: plus#_A(x1,x2) = 0 s_A(x1) = x1 + 15 if_A(x1,x2,x3) = max{8, x2 + 4, x3} gt_A(x1,x2) = max{15, x1 - 31, x2 - 16} not_A(x1) = max{16, x1 - 46} id_A(x1) = x1 + 11 true_A = 1 false_A = 12 zero_A = 0 plus#!_A(x1,x2) = max{26, x1 + 14, x2 + 5} s!_A(x1) = max{27, x1 + 21} if!_A(x1,x2,x3) = 29 gt!_A(x1,x2) = max{34, x1 - 16, x2 + 30} not!_A(x1) = 32 id!_A(x1) = x1 + 29 true!_A = 26 false!_A = 31 zero!_A = 0 2. marked-algebra reduction triple (>=A, >=A!, >A!): matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: plus#_A(x1,x2) = 0 s_A(x1) = 6 if_A(x1,x2,x3) = x2 + x3 + 3 gt_A(x1,x2) = 1 not_A(x1) = 5 id_A(x1) = x1 + 1 true_A() = 1 false_A() = 1 zero_A() = 1 plus#!_A(x1,x2) = 7 s!_A(x1) = 9 if!_A(x1,x2,x3) = x3 gt!_A(x1,x2) = 14 not!_A(x1) = 8 id!_A(x1) = 6 true!_A() = 1 false!_A() = 1 zero!_A() = 0 partial status: pi(plus#) = [] pi(s) = [1] pi(if) = [2, 3] pi(gt) = [] pi(not) = [] pi(id) = [1] pi(true) = [] pi(false) = [] pi(zero) = [] The following rules are removed: p1 -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: plus#(id(x),s(y)) -> plus#(x,if(gt(s(y),y),y,s(y))) p2: plus#(s(x),x) -> plus#(if(gt(x,x),id(x),id(x)),s(x)) and R consists of: r1: minus(x,|0|()) -> x r2: minus(s(x),s(y)) -> minus(x,y) r3: quot(|0|(),s(y)) -> |0|() r4: quot(s(x),s(y)) -> s(quot(minus(x,y),s(y))) r5: minus(minus(x,y),z) -> minus(x,plus(y,z)) r6: plus(s(x),s(y)) -> s(s(plus(if(gt(x,y),x,y),if(not(gt(x,y)),id(x),id(y))))) r7: plus(s(x),x) -> plus(if(gt(x,x),id(x),id(x)),s(x)) r8: plus(zero(),y) -> y r9: plus(id(x),s(y)) -> s(plus(x,if(gt(s(y),y),y,s(y)))) r10: id(x) -> x r11: if(true(),x,y) -> x r12: if(false(),x,y) -> y r13: not(x) -> if(x,false(),true()) r14: gt(s(x),zero()) -> true() r15: gt(zero(),y) -> false() r16: gt(s(x),s(y)) -> gt(x,y) The estimated dependency graph contains the following SCCs: {p1, p2} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: plus#(id(x),s(y)) -> plus#(x,if(gt(s(y),y),y,s(y))) p2: plus#(s(x),x) -> plus#(if(gt(x,x),id(x),id(x)),s(x)) and R consists of: r1: minus(x,|0|()) -> x r2: minus(s(x),s(y)) -> minus(x,y) r3: quot(|0|(),s(y)) -> |0|() r4: quot(s(x),s(y)) -> s(quot(minus(x,y),s(y))) r5: minus(minus(x,y),z) -> minus(x,plus(y,z)) r6: plus(s(x),s(y)) -> s(s(plus(if(gt(x,y),x,y),if(not(gt(x,y)),id(x),id(y))))) r7: plus(s(x),x) -> plus(if(gt(x,x),id(x),id(x)),s(x)) r8: plus(zero(),y) -> y r9: plus(id(x),s(y)) -> s(plus(x,if(gt(s(y),y),y,s(y)))) r10: id(x) -> x r11: if(true(),x,y) -> x r12: if(false(),x,y) -> y r13: not(x) -> if(x,false(),true()) r14: gt(s(x),zero()) -> true() r15: gt(zero(),y) -> false() r16: gt(s(x),s(y)) -> gt(x,y) The set of usable rules consists of r10, r11, r12, r14, r15, r16 Take the reduction pair: generalized weighted path order (>=MG, >G) base order 1: trivial reduction triple (T x T, T x T, Φ) base order 2: lexicographic combination of reduction triples: 1. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: plus#_A(x1,x2) = 0 id_A(x1) = max{3, x1 + 1} s_A(x1) = 10 if_A(x1,x2,x3) = max{27, x2 + 10, x3} gt_A(x1,x2) = 8 true_A = 6 false_A = 2 zero_A = 24 plus#!_A(x1,x2) = 7 id!_A(x1) = 7 s!_A(x1) = x1 + 24 if!_A(x1,x2,x3) = max{23, x3 + 21} gt!_A(x1,x2) = max{12, x2 + 2} true!_A = 25 false!_A = 1 zero!_A = 26 2. marked-algebra reduction triple (>=A, >=A!, >A!): matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: plus#_A(x1,x2) = 0 id_A(x1) = x1 + 6 s_A(x1) = 4 if_A(x1,x2,x3) = x2 + x3 + 5 gt_A(x1,x2) = 1 true_A() = 1 false_A() = 1 zero_A() = 1 plus#!_A(x1,x2) = 0 id!_A(x1) = 0 s!_A(x1) = 19 if!_A(x1,x2,x3) = 6 gt!_A(x1,x2) = 8 true!_A() = 0 false!_A() = 0 zero!_A() = 1 partial status: pi(plus#) = [1] pi(id) = [1] pi(s) = [1] pi(if) = [2, 3] pi(gt) = [2] pi(true) = [] pi(false) = [] pi(zero) = [] The following rules are removed: p1, p2 Then no dependency pair remains. -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: gt#(s(x),s(y)) -> gt#(x,y) and R consists of: r1: minus(x,|0|()) -> x r2: minus(s(x),s(y)) -> minus(x,y) r3: quot(|0|(),s(y)) -> |0|() r4: quot(s(x),s(y)) -> s(quot(minus(x,y),s(y))) r5: minus(minus(x,y),z) -> minus(x,plus(y,z)) r6: plus(s(x),s(y)) -> s(s(plus(if(gt(x,y),x,y),if(not(gt(x,y)),id(x),id(y))))) r7: plus(s(x),x) -> plus(if(gt(x,x),id(x),id(x)),s(x)) r8: plus(zero(),y) -> y r9: plus(id(x),s(y)) -> s(plus(x,if(gt(s(y),y),y,s(y)))) r10: id(x) -> x r11: if(true(),x,y) -> x r12: if(false(),x,y) -> y r13: not(x) -> if(x,false(),true()) r14: gt(s(x),zero()) -> true() r15: gt(zero(),y) -> false() r16: gt(s(x),s(y)) -> gt(x,y) The set of usable rules consists of (no rules) Take the reduction pair: generalized weighted path order (>=MG, >G) base order 1: trivial reduction triple (T x T, T x T, Φ) base order 2: lexicographic combination of reduction triples: 1. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: gt#_A(x1,x2) = max{0, x1 - 17, x2 - 17} s_A(x1) = x1 + 16 gt#!_A(x1,x2) = max{0, x1 - 17} s!_A(x1) = max{0, x1 - 16} 2. marked-algebra reduction triple (>=A, >=A!, >A!): matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: gt#_A(x1,x2) = x1 + x2 s_A(x1) = x1 + 2 gt#!_A(x1,x2) = 1 s!_A(x1) = 2 partial status: pi(gt#) = [1] pi(s) = [1] The following rules are removed: p1 Then no dependency pair remains.