YES We show the termination of the TRS R: minus(x,|0|()) -> x minus(s(x),s(y)) -> minus(x,y) double(|0|()) -> |0|() double(s(x)) -> s(s(double(x))) 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: double#(s(x)) -> double#(x) p3: plus#(s(x),s(y)) -> plus#(if(gt(x,y),x,y),if(not(gt(x,y)),id(x),id(y))) p4: plus#(s(x),s(y)) -> if#(gt(x,y),x,y) p5: plus#(s(x),s(y)) -> gt#(x,y) p6: plus#(s(x),s(y)) -> if#(not(gt(x,y)),id(x),id(y)) p7: plus#(s(x),s(y)) -> not#(gt(x,y)) p8: plus#(s(x),s(y)) -> id#(x) p9: plus#(s(x),s(y)) -> id#(y) p10: plus#(s(x),x) -> plus#(if(gt(x,x),id(x),id(x)),s(x)) p11: plus#(s(x),x) -> if#(gt(x,x),id(x),id(x)) p12: plus#(s(x),x) -> gt#(x,x) p13: plus#(s(x),x) -> id#(x) p14: plus#(id(x),s(y)) -> plus#(x,if(gt(s(y),y),y,s(y))) p15: plus#(id(x),s(y)) -> if#(gt(s(y),y),y,s(y)) p16: plus#(id(x),s(y)) -> gt#(s(y),y) p17: not#(x) -> if#(x,false(),true()) p18: 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: double(|0|()) -> |0|() r4: double(s(x)) -> s(s(double(x))) r5: plus(s(x),s(y)) -> s(s(plus(if(gt(x,y),x,y),if(not(gt(x,y)),id(x),id(y))))) r6: plus(s(x),x) -> plus(if(gt(x,x),id(x),id(x)),s(x)) r7: plus(zero(),y) -> y r8: plus(id(x),s(y)) -> s(plus(x,if(gt(s(y),y),y,s(y)))) r9: id(x) -> x r10: if(true(),x,y) -> x r11: if(false(),x,y) -> y r12: not(x) -> if(x,false(),true()) r13: gt(s(x),zero()) -> true() r14: gt(zero(),y) -> false() r15: gt(s(x),s(y)) -> gt(x,y) The estimated dependency graph contains the following SCCs: {p1} {p2} {p3, p10, p14} {p18} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: minus#(s(x),s(y)) -> minus#(x,y) and R consists of: r1: minus(x,|0|()) -> x r2: minus(s(x),s(y)) -> minus(x,y) r3: double(|0|()) -> |0|() r4: double(s(x)) -> s(s(double(x))) r5: plus(s(x),s(y)) -> s(s(plus(if(gt(x,y),x,y),if(not(gt(x,y)),id(x),id(y))))) r6: plus(s(x),x) -> plus(if(gt(x,x),id(x),id(x)),s(x)) r7: plus(zero(),y) -> y r8: plus(id(x),s(y)) -> s(plus(x,if(gt(s(y),y),y,s(y)))) r9: id(x) -> x r10: if(true(),x,y) -> x r11: if(false(),x,y) -> y r12: not(x) -> if(x,false(),true()) r13: gt(s(x),zero()) -> true() r14: gt(zero(),y) -> false() r15: 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: minus#_A(x1,x2) = max{0, x1 - 1, x2 - 1} s_A(x1) = x1 minus#!_A(x1,x2) = max{10, x1 + 1} s!_A(x1) = 9 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 + x2 s_A(x1) = x1 + 3 minus#!_A(x1,x2) = x1 + x2 + 4 s!_A(x1) = 3 partial status: pi(minus#) = [2] pi(s) = [1] 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: double#(s(x)) -> double#(x) and R consists of: r1: minus(x,|0|()) -> x r2: minus(s(x),s(y)) -> minus(x,y) r3: double(|0|()) -> |0|() r4: double(s(x)) -> s(s(double(x))) r5: plus(s(x),s(y)) -> s(s(plus(if(gt(x,y),x,y),if(not(gt(x,y)),id(x),id(y))))) r6: plus(s(x),x) -> plus(if(gt(x,x),id(x),id(x)),s(x)) r7: plus(zero(),y) -> y r8: plus(id(x),s(y)) -> s(plus(x,if(gt(s(y),y),y,s(y)))) r9: id(x) -> x r10: if(true(),x,y) -> x r11: if(false(),x,y) -> y r12: not(x) -> if(x,false(),true()) r13: gt(s(x),zero()) -> true() r14: gt(zero(),y) -> false() r15: 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: double#_A(x1) = max{0, x1 - 1} s_A(x1) = max{3, x1} double#!_A(x1) = max{1, x1 - 4} s!_A(x1) = x1 2. marked-algebra reduction triple (>=A, >=A!, >A!): matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: double#_A(x1) = x1 s_A(x1) = x1 + 1 double#!_A(x1) = x1 + 4 s!_A(x1) = 3 partial status: pi(double#) = [] pi(s) = [] 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: 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: double(|0|()) -> |0|() r4: double(s(x)) -> s(s(double(x))) r5: plus(s(x),s(y)) -> s(s(plus(if(gt(x,y),x,y),if(not(gt(x,y)),id(x),id(y))))) r6: plus(s(x),x) -> plus(if(gt(x,x),id(x),id(x)),s(x)) r7: plus(zero(),y) -> y r8: plus(id(x),s(y)) -> s(plus(x,if(gt(s(y),y),y,s(y)))) r9: id(x) -> x r10: if(true(),x,y) -> x r11: if(false(),x,y) -> y r12: not(x) -> if(x,false(),true()) r13: gt(s(x),zero()) -> true() r14: gt(zero(),y) -> false() r15: gt(s(x),s(y)) -> gt(x,y) The set of usable rules consists of r9, r10, r11, r12, r13, r14, r15 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) = max{105, x1 + 97} if_A(x1,x2,x3) = max{63, x2 + 32, x3} gt_A(x1,x2) = max{95, x1 - 204, x2 - 99} not_A(x1) = max{95, x1 - 291} id_A(x1) = max{64, x1 + 31} true_A = 95 false_A = 32 zero_A = 98 plus#!_A(x1,x2) = max{x1 + 23, x2 + 13} s!_A(x1) = x1 + 225 if!_A(x1,x2,x3) = max{221, x3 - 94} gt!_A(x1,x2) = 224 not!_A(x1) = x1 + 430 id!_A(x1) = 119 true!_A = 223 false!_A = 221 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) = 2 if_A(x1,x2,x3) = x2 + x3 + 1 gt_A(x1,x2) = 1 not_A(x1) = 3 id_A(x1) = x1 + 1 true_A() = 1 false_A() = 1 zero_A() = 1 plus#!_A(x1,x2) = 5 s!_A(x1) = 4 if!_A(x1,x2,x3) = 2 gt!_A(x1,x2) = 2 not!_A(x1) = 0 id!_A(x1) = 4 true!_A() = 5 false!_A() = 1 zero!_A() = 0 partial status: pi(plus#) = [] pi(s) = [] pi(if) = [2, 3] pi(gt) = [] pi(not) = [1] pi(id) = [1] pi(true) = [] pi(false) = [] pi(zero) = [] The following rules are removed: p1, p3 -- 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))) and R consists of: r1: minus(x,|0|()) -> x r2: minus(s(x),s(y)) -> minus(x,y) r3: double(|0|()) -> |0|() r4: double(s(x)) -> s(s(double(x))) r5: plus(s(x),s(y)) -> s(s(plus(if(gt(x,y),x,y),if(not(gt(x,y)),id(x),id(y))))) r6: plus(s(x),x) -> plus(if(gt(x,x),id(x),id(x)),s(x)) r7: plus(zero(),y) -> y r8: plus(id(x),s(y)) -> s(plus(x,if(gt(s(y),y),y,s(y)))) r9: id(x) -> x r10: if(true(),x,y) -> x r11: if(false(),x,y) -> y r12: not(x) -> if(x,false(),true()) r13: gt(s(x),zero()) -> true() r14: gt(zero(),y) -> false() r15: gt(s(x),s(y)) -> gt(x,y) The estimated dependency graph contains the following SCCs: {p1} -- 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))) and R consists of: r1: minus(x,|0|()) -> x r2: minus(s(x),s(y)) -> minus(x,y) r3: double(|0|()) -> |0|() r4: double(s(x)) -> s(s(double(x))) r5: plus(s(x),s(y)) -> s(s(plus(if(gt(x,y),x,y),if(not(gt(x,y)),id(x),id(y))))) r6: plus(s(x),x) -> plus(if(gt(x,x),id(x),id(x)),s(x)) r7: plus(zero(),y) -> y r8: plus(id(x),s(y)) -> s(plus(x,if(gt(s(y),y),y,s(y)))) r9: id(x) -> x r10: if(true(),x,y) -> x r11: if(false(),x,y) -> y r12: not(x) -> if(x,false(),true()) r13: gt(s(x),zero()) -> true() r14: gt(zero(),y) -> false() r15: gt(s(x),s(y)) -> gt(x,y) The set of usable rules consists of r11 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) = max{0, x1 - 63} id_A(x1) = x1 + 62 s_A(x1) = x1 + 79 if_A(x1,x2,x3) = max{194, x2 - 10, x3 + 25} gt_A(x1,x2) = max{x1 - 39, x2 + 28} false_A = 0 plus#!_A(x1,x2) = max{45, x1 - 63} id!_A(x1) = max{44, x1 + 17} s!_A(x1) = x1 + 44 if!_A(x1,x2,x3) = max{x1 + 2, x3 + 8} gt!_A(x1,x2) = 44 false!_A = 85 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) = x1 id_A(x1) = x1 + 3 s_A(x1) = 3 if_A(x1,x2,x3) = x3 + 1 gt_A(x1,x2) = 1 false_A() = 2 plus#!_A(x1,x2) = x1 + 2 id!_A(x1) = 3 s!_A(x1) = x1 + 4 if!_A(x1,x2,x3) = 2 gt!_A(x1,x2) = 4 false!_A() = 0 partial status: pi(plus#) = [1] pi(id) = [1] pi(s) = [1] pi(if) = [1, 3] pi(gt) = [1] 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: 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: double(|0|()) -> |0|() r4: double(s(x)) -> s(s(double(x))) r5: plus(s(x),s(y)) -> s(s(plus(if(gt(x,y),x,y),if(not(gt(x,y)),id(x),id(y))))) r6: plus(s(x),x) -> plus(if(gt(x,x),id(x),id(x)),s(x)) r7: plus(zero(),y) -> y r8: plus(id(x),s(y)) -> s(plus(x,if(gt(s(y),y),y,s(y)))) r9: id(x) -> x r10: if(true(),x,y) -> x r11: if(false(),x,y) -> y r12: not(x) -> if(x,false(),true()) r13: gt(s(x),zero()) -> true() r14: gt(zero(),y) -> false() r15: 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 - 5, x2 - 7} s_A(x1) = max{9, x1 + 6} gt#!_A(x1,x2) = max{1, x1 - 284, x2 - 10} s!_A(x1) = max{0, x1 - 285} 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) = x1 + x2 + 2 s!_A(x1) = 1 partial status: pi(gt#) = [2] pi(s) = [1] The following rules are removed: p1 Then no dependency pair remains.