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)) quot(|0|(),s(y)) -> |0|() quot(s(x),s(y)) -> s(quot(minus(x,y),s(y))) log(s(|0|())) -> |0|() log(s(s(x))) -> s(log(s(quot(x,s(s(|0|())))))) -- 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: quot#(s(x),s(y)) -> quot#(minus(x,y),s(y)) p6: quot#(s(x),s(y)) -> minus#(x,y) p7: log#(s(s(x))) -> log#(s(quot(x,s(s(|0|()))))) p8: log#(s(s(x))) -> quot#(x,s(s(|0|()))) 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: quot(|0|(),s(y)) -> |0|() r9: quot(s(x),s(y)) -> s(quot(minus(x,y),s(y))) r10: log(s(|0|())) -> |0|() r11: log(s(s(x))) -> s(log(s(quot(x,s(s(|0|())))))) The estimated dependency graph contains the following SCCs: {p7} {p5} {p2, p4} {p1} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: log#(s(s(x))) -> log#(s(quot(x,s(s(|0|()))))) 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: quot(|0|(),s(y)) -> |0|() r9: quot(s(x),s(y)) -> s(quot(minus(x,y),s(y))) r10: log(s(|0|())) -> |0|() r11: log(s(s(x))) -> s(log(s(quot(x,s(s(|0|())))))) The set of usable rules consists of r1, r2, r3, r4, r5, r6, r7, r8, r9, r10 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!): matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: log#_A(x1) = x1 s_A(x1) = x1 + 4 quot_A(x1,x2) = x1 |0|_A() = 0 le_A(x1,x2) = 1 true_A() = 1 false_A() = 1 minus_A(x1,x2) = x1 if_minus_A(x1,x2,x3) = x2 log_A(x1) = 0 log#!_A(x1) = x1 s!_A(x1) = 9 quot!_A(x1,x2) = x2 |0|!_A() = 5 le!_A(x1,x2) = 8 true!_A() = 0 false!_A() = 7 minus!_A(x1,x2) = x1 + 6 if_minus!_A(x1,x2,x3) = x2 + 5 log!_A(x1) = 0 2. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: log#_A(x1) = max{22, x1 + 1} s_A(x1) = max{10, x1} quot_A(x1,x2) = max{21, x1} |0|_A = 0 le_A(x1,x2) = 25 true_A = 13 false_A = 25 minus_A(x1,x2) = 11 if_minus_A(x1,x2,x3) = max{9, x1 - 14} log_A(x1) = max{11, x1 - 21} log#!_A(x1) = max{1, x1 - 8} s!_A(x1) = 0 quot!_A(x1,x2) = max{0, x1 - 7, x2 - 22} |0|!_A = 3 le!_A(x1,x2) = 0 true!_A = 4 false!_A = 6 minus!_A(x1,x2) = max{x1 - 1, x2 + 5} if_minus!_A(x1,x2,x3) = max{4, x2 - 9} log!_A(x1) = max{11, x1 - 11} partial status: pi(log#) = [] pi(s) = [] pi(quot) = [2] pi(|0|) = [] pi(le) = [] pi(true) = [] pi(false) = [] pi(minus) = [1, 2] pi(if_minus) = [] pi(log) = [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: quot#(s(x),s(y)) -> quot#(minus(x,y),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: quot(|0|(),s(y)) -> |0|() r9: quot(s(x),s(y)) -> s(quot(minus(x,y),s(y))) r10: log(s(|0|())) -> |0|() r11: log(s(s(x))) -> s(log(s(quot(x,s(s(|0|())))))) The set of usable rules consists of r2, 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!): matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: quot#_A(x1,x2) = 0 s_A(x1) = 2 minus_A(x1,x2) = x2 + 3 le_A(x1,x2) = x2 |0|_A() = 1 false_A() = 1 if_minus_A(x1,x2,x3) = x3 + 3 true_A() = 1 quot#!_A(x1,x2) = 5 s!_A(x1) = 6 minus!_A(x1,x2) = 1 le!_A(x1,x2) = x2 + 5 |0|!_A() = 3 false!_A() = 2 if_minus!_A(x1,x2,x3) = 0 true!_A() = 4 2. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: quot#_A(x1,x2) = max{0, x1 - 11, x2 - 58} s_A(x1) = max{53, x1 + 10} minus_A(x1,x2) = max{7, x1} le_A(x1,x2) = max{45, x1 - 9, x2 - 1} |0|_A = 5 false_A = 45 if_minus_A(x1,x2,x3) = max{16, x2} true_A = 45 quot#!_A(x1,x2) = max{1, x1 - 8} s!_A(x1) = max{0, x1 - 12} minus!_A(x1,x2) = max{4, x1 + 3, x2 + 2} le!_A(x1,x2) = max{x1 + 1, x2 + 1} |0|!_A = 0 false!_A = 5 if_minus!_A(x1,x2,x3) = max{0, x2 - 50} true!_A = 6 partial status: pi(quot#) = [] pi(s) = [] pi(minus) = [1] pi(le) = [1, 2] pi(|0|) = [] pi(false) = [] pi(if_minus) = [2] pi(true) = [] 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: 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: quot(|0|(),s(y)) -> |0|() r9: quot(s(x),s(y)) -> s(quot(minus(x,y),s(y))) r10: log(s(|0|())) -> |0|() r11: log(s(s(x))) -> s(log(s(quot(x,s(s(|0|())))))) The set of usable rules consists of r1, r4, r6, r8, r10 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!): matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: if_minus#_A(x1,x2,x3) = x2 false_A() = 4 s_A(x1) = x1 + 2 minus#_A(x1,x2) = x1 le_A(x1,x2) = x1 + 1 |0|_A() = 0 true_A() = 1 minus_A(x1,x2) = x2 + 3 if_minus_A(x1,x2,x3) = 4 quot_A(x1,x2) = 3 log_A(x1) = x1 if_minus#!_A(x1,x2,x3) = 2 false!_A() = 4 s!_A(x1) = 7 minus#!_A(x1,x2) = 3 le!_A(x1,x2) = 2 |0|!_A() = 0 true!_A() = 1 minus!_A(x1,x2) = x2 + 5 if_minus!_A(x1,x2,x3) = 7 quot!_A(x1,x2) = x2 + 4 log!_A(x1) = 9 2. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: if_minus#_A(x1,x2,x3) = max{1, x2 - 17, x3 - 2} false_A = 0 s_A(x1) = max{16, x1 + 6} minus#_A(x1,x2) = max{1, x1 - 16, x2 - 2} le_A(x1,x2) = max{13, x1 - 16, x2 - 10} |0|_A = 0 true_A = 0 minus_A(x1,x2) = max{11, x1 - 18, x2 - 4} if_minus_A(x1,x2,x3) = max{15, x1 - 1, x2 - 19, x3 - 1} quot_A(x1,x2) = max{11, x1 - 31, x2 - 36} log_A(x1) = max{7, x1 - 24} if_minus#!_A(x1,x2,x3) = 1 false!_A = 3 s!_A(x1) = 2 minus#!_A(x1,x2) = max{2, x1 - 17, x2 - 1} le!_A(x1,x2) = 2 |0|!_A = 40 true!_A = 41 minus!_A(x1,x2) = max{2, x1 - 29, x2 - 40} if_minus!_A(x1,x2,x3) = max{2, x1 - 14, x2 - 17} quot!_A(x1,x2) = max{0, x1 - 36, x2 - 47} log!_A(x1) = max{41, x1 + 17} partial status: pi(if_minus#) = [2] pi(false) = [] pi(s) = [1] pi(minus#) = [1] pi(le) = [] pi(|0|) = [] pi(true) = [] pi(minus) = [2] pi(if_minus) = [1, 3] pi(quot) = [1, 2] pi(log) = [1] 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: 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: quot(|0|(),s(y)) -> |0|() r9: quot(s(x),s(y)) -> s(quot(minus(x,y),s(y))) r10: log(s(|0|())) -> |0|() r11: log(s(s(x))) -> s(log(s(quot(x,s(s(|0|())))))) The set of usable rules consists of r4, r8, r10 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!): matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: le#_A(x1,x2) = x1 + x2 s_A(x1) = x1 + 1 minus_A(x1,x2) = x1 + 2 |0|_A() = 3 quot_A(x1,x2) = x1 + 2 log_A(x1) = x1 le#!_A(x1,x2) = x1 + x2 s!_A(x1) = 2 minus!_A(x1,x2) = 5 |0|!_A() = 1 quot!_A(x1,x2) = 4 log!_A(x1) = 3 2. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: le#_A(x1,x2) = 0 s_A(x1) = max{23, x1 - 27} minus_A(x1,x2) = max{13, x1 - 132, x2 - 132} |0|_A = 11 quot_A(x1,x2) = max{18, x1 - 33, x2 + 17} log_A(x1) = max{101, x1 - 22} le#!_A(x1,x2) = max{43, x2 - 24} s!_A(x1) = max{42, x1 + 30} minus!_A(x1,x2) = max{57, x1 - 23, x2 - 25} |0|!_A = 2 quot!_A(x1,x2) = max{56, x2 + 33} log!_A(x1) = x1 + 109 partial status: pi(le#) = [] pi(s) = [] pi(minus) = [1] pi(|0|) = [] pi(quot) = [] pi(log) = [] The following rules are removed: p1 Then no dependency pair remains.