YES We show the termination of the TRS R: le(|0|(),y) -> true() le(s(x),|0|()) -> false() le(s(x),s(y)) -> le(x,y) minus(|0|(),y) -> |0|() minus(s(x),y) -> if_minus(le(s(x),y),s(x),y) if_minus(true(),s(x),y) -> |0|() if_minus(false(),s(x),y) -> s(minus(x,y)) mod(|0|(),y) -> |0|() mod(s(x),|0|()) -> |0|() mod(s(x),s(y)) -> if_mod(le(y,x),s(x),s(y)) if_mod(true(),s(x),s(y)) -> mod(minus(x,y),s(y)) if_mod(false(),s(x),s(y)) -> s(x) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: le#(s(x),s(y)) -> le#(x,y) p2: minus#(s(x),y) -> if_minus#(le(s(x),y),s(x),y) p3: minus#(s(x),y) -> le#(s(x),y) p4: if_minus#(false(),s(x),y) -> minus#(x,y) p5: mod#(s(x),s(y)) -> if_mod#(le(y,x),s(x),s(y)) p6: mod#(s(x),s(y)) -> le#(y,x) p7: if_mod#(true(),s(x),s(y)) -> mod#(minus(x,y),s(y)) p8: if_mod#(true(),s(x),s(y)) -> minus#(x,y) and R consists of: r1: le(|0|(),y) -> true() r2: le(s(x),|0|()) -> false() r3: le(s(x),s(y)) -> le(x,y) r4: minus(|0|(),y) -> |0|() r5: minus(s(x),y) -> if_minus(le(s(x),y),s(x),y) r6: if_minus(true(),s(x),y) -> |0|() r7: if_minus(false(),s(x),y) -> s(minus(x,y)) r8: mod(|0|(),y) -> |0|() r9: mod(s(x),|0|()) -> |0|() r10: mod(s(x),s(y)) -> if_mod(le(y,x),s(x),s(y)) r11: if_mod(true(),s(x),s(y)) -> mod(minus(x,y),s(y)) r12: if_mod(false(),s(x),s(y)) -> s(x) The estimated dependency graph contains the following SCCs: {p5, p7} {p2, p4} {p1} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: if_mod#(true(),s(x),s(y)) -> mod#(minus(x,y),s(y)) p2: mod#(s(x),s(y)) -> if_mod#(le(y,x),s(x),s(y)) and R consists of: r1: le(|0|(),y) -> true() r2: le(s(x),|0|()) -> false() r3: le(s(x),s(y)) -> le(x,y) r4: minus(|0|(),y) -> |0|() r5: minus(s(x),y) -> if_minus(le(s(x),y),s(x),y) r6: if_minus(true(),s(x),y) -> |0|() r7: if_minus(false(),s(x),y) -> s(minus(x,y)) r8: mod(|0|(),y) -> |0|() r9: mod(s(x),|0|()) -> |0|() r10: mod(s(x),s(y)) -> if_mod(le(y,x),s(x),s(y)) r11: if_mod(true(),s(x),s(y)) -> mod(minus(x,y),s(y)) r12: if_mod(false(),s(x),s(y)) -> s(x) The set of usable rules consists of r1, r2, r3, r4, r5, r6, r7 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: if_mod#_A(x1,x2,x3) = max{1, x1 - 23, x3 - 32} true_A = 6 s_A(x1) = x1 + 31 mod#_A(x1,x2) = max{1, x2 - 32} minus_A(x1,x2) = x1 le_A(x1,x2) = max{23, x1 + 1} |0|_A = 13 false_A = 32 if_minus_A(x1,x2,x3) = max{13, x1 - 1, x2} if_mod#!_A(x1,x2,x3) = 8 true!_A = 5 s!_A(x1) = x1 + 19 mod#!_A(x1,x2) = 8 minus!_A(x1,x2) = x1 + 17 le!_A(x1,x2) = max{6, x1 - 29} |0|!_A = 4 false!_A = 3 if_minus!_A(x1,x2,x3) = max{5, x1 - 24, x2 - 15} 2. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: if_mod#_A(x1,x2,x3) = max{24, x1 + 16} true_A = 2 s_A(x1) = 3 mod#_A(x1,x2) = 24 minus_A(x1,x2) = x1 le_A(x1,x2) = 8 |0|_A = 0 false_A = 2 if_minus_A(x1,x2,x3) = max{1, x1 - 9, x2} if_mod#!_A(x1,x2,x3) = x2 + 1 true!_A = 8 s!_A(x1) = x1 + 6 mod#!_A(x1,x2) = max{4, x2 + 1} minus!_A(x1,x2) = 0 le!_A(x1,x2) = 7 |0|!_A = 6 false!_A = 7 if_minus!_A(x1,x2,x3) = max{4, x1 - 1} partial status: pi(if_mod#) = [2] pi(true) = [] pi(s) = [] pi(mod#) = [1] pi(minus) = [] pi(le) = [] pi(|0|) = [] pi(false) = [] pi(if_minus) = [2] The following rules are removed: p1 -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: mod#(s(x),s(y)) -> if_mod#(le(y,x),s(x),s(y)) and R consists of: r1: le(|0|(),y) -> true() r2: le(s(x),|0|()) -> false() r3: le(s(x),s(y)) -> le(x,y) r4: minus(|0|(),y) -> |0|() r5: minus(s(x),y) -> if_minus(le(s(x),y),s(x),y) r6: if_minus(true(),s(x),y) -> |0|() r7: if_minus(false(),s(x),y) -> s(minus(x,y)) r8: mod(|0|(),y) -> |0|() r9: mod(s(x),|0|()) -> |0|() r10: mod(s(x),s(y)) -> if_mod(le(y,x),s(x),s(y)) r11: if_mod(true(),s(x),s(y)) -> mod(minus(x,y),s(y)) r12: if_mod(false(),s(x),s(y)) -> s(x) The estimated dependency graph contains the following SCCs: (no SCCs) -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: if_minus#(false(),s(x),y) -> minus#(x,y) p2: minus#(s(x),y) -> if_minus#(le(s(x),y),s(x),y) and R consists of: r1: le(|0|(),y) -> true() r2: le(s(x),|0|()) -> false() r3: le(s(x),s(y)) -> le(x,y) r4: minus(|0|(),y) -> |0|() r5: minus(s(x),y) -> if_minus(le(s(x),y),s(x),y) r6: if_minus(true(),s(x),y) -> |0|() r7: if_minus(false(),s(x),y) -> s(minus(x,y)) r8: mod(|0|(),y) -> |0|() r9: mod(s(x),|0|()) -> |0|() r10: mod(s(x),s(y)) -> if_mod(le(y,x),s(x),s(y)) r11: if_mod(true(),s(x),s(y)) -> mod(minus(x,y),s(y)) r12: if_mod(false(),s(x),s(y)) -> s(x) The set of usable rules consists of r1, r2, r3 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: if_minus#_A(x1,x2,x3) = max{0, x1 - 3, x2 - 30, x3 - 11} false_A = 2 s_A(x1) = max{20, x1 + 5} minus#_A(x1,x2) = max{0, x1 - 30, x2 - 11} le_A(x1,x2) = max{2, x1 - 27, x2 - 9} |0|_A = 8 true_A = 0 if_minus#!_A(x1,x2,x3) = max{6, x1 - 18, x2 - 42, x3 - 20} false!_A = 3 s!_A(x1) = max{5, x1 - 40} minus#!_A(x1,x2) = max{6, x1 - 41, x2 - 20} le!_A(x1,x2) = max{5, x1 - 45, x2 - 21} |0|!_A = 2 true!_A = 1 2. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: if_minus#_A(x1,x2,x3) = max{0, x1 - 15, x2 - 43, x3 - 17} false_A = 14 s_A(x1) = max{27, x1 + 4} minus#_A(x1,x2) = max{0, x1 - 43, x2 - 17} le_A(x1,x2) = max{14, x1 - 28, x2 - 20} |0|_A = 19 true_A = 0 if_minus#!_A(x1,x2,x3) = max{4, x1 - 67, x2 - 97, x3 - 69} false!_A = 4 s!_A(x1) = max{4, x1 - 90} minus#!_A(x1,x2) = max{4, x1 - 94, x2 - 69} le!_A(x1,x2) = max{3, x1 - 118, x2 - 91} |0|!_A = 3 true!_A = 2 partial status: pi(if_minus#) = [2] pi(false) = [] pi(s) = [1] pi(minus#) = [1] pi(le) = [] pi(|0|) = [] pi(true) = [] The following rules are removed: p1 -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: minus#(s(x),y) -> if_minus#(le(s(x),y),s(x),y) and R consists of: r1: le(|0|(),y) -> true() r2: le(s(x),|0|()) -> false() r3: le(s(x),s(y)) -> le(x,y) r4: minus(|0|(),y) -> |0|() r5: minus(s(x),y) -> if_minus(le(s(x),y),s(x),y) r6: if_minus(true(),s(x),y) -> |0|() r7: if_minus(false(),s(x),y) -> s(minus(x,y)) r8: mod(|0|(),y) -> |0|() r9: mod(s(x),|0|()) -> |0|() r10: mod(s(x),s(y)) -> if_mod(le(y,x),s(x),s(y)) r11: if_mod(true(),s(x),s(y)) -> mod(minus(x,y),s(y)) r12: if_mod(false(),s(x),s(y)) -> s(x) The estimated dependency graph contains the following SCCs: (no SCCs) -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: le#(s(x),s(y)) -> le#(x,y) and R consists of: r1: le(|0|(),y) -> true() r2: le(s(x),|0|()) -> false() r3: le(s(x),s(y)) -> le(x,y) r4: minus(|0|(),y) -> |0|() r5: minus(s(x),y) -> if_minus(le(s(x),y),s(x),y) r6: if_minus(true(),s(x),y) -> |0|() r7: if_minus(false(),s(x),y) -> s(minus(x,y)) r8: mod(|0|(),y) -> |0|() r9: mod(s(x),|0|()) -> |0|() r10: mod(s(x),s(y)) -> if_mod(le(y,x),s(x),s(y)) r11: if_mod(true(),s(x),s(y)) -> mod(minus(x,y),s(y)) r12: if_mod(false(),s(x),s(y)) -> s(x) The set of usable rules consists of r1, r2, r4, r6 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: le#_A(x1,x2) = 0 s_A(x1) = max{1, x1 - 9} le_A(x1,x2) = max{13, x1 - 4} |0|_A = 3 true_A = 1 false_A = 10 minus_A(x1,x2) = max{8, x1 - 7, x2 - 7} if_minus_A(x1,x2,x3) = max{3, x1 - 12, x2 - 7, x3 - 7} le#!_A(x1,x2) = 0 s!_A(x1) = 13 le!_A(x1,x2) = 2 |0|!_A = 6 true!_A = 0 false!_A = 1 minus!_A(x1,x2) = x2 + 18 if_minus!_A(x1,x2,x3) = max{x1 + 4, x3 + 18} 2. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: le#_A(x1,x2) = max{x1, x2} s_A(x1) = x1 + 31 le_A(x1,x2) = max{14, x1 - 16} |0|_A = 52 true_A = 1 false_A = 15 minus_A(x1,x2) = max{64, x2 + 48} if_minus_A(x1,x2,x3) = max{x1 + 50, x2 + 33, x3 - 1} le#!_A(x1,x2) = 0 s!_A(x1) = max{67, x1 + 5} le!_A(x1,x2) = 3 |0|!_A = 69 true!_A = 70 false!_A = 1 minus!_A(x1,x2) = 4 if_minus!_A(x1,x2,x3) = max{68, x1 - 13} partial status: pi(le#) = [1] pi(s) = [1] pi(le) = [] pi(|0|) = [] pi(true) = [] pi(false) = [] pi(minus) = [] pi(if_minus) = [1] The following rules are removed: p1 Then no dependency pair remains.