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) pred(s(x)) -> x minus(x,|0|()) -> x minus(x,s(y)) -> pred(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#(x,s(y)) -> pred#(minus(x,y)) p3: minus#(x,s(y)) -> minus#(x,y) p4: mod#(s(x),s(y)) -> if_mod#(le(y,x),s(x),s(y)) p5: mod#(s(x),s(y)) -> le#(y,x) p6: if_mod#(true(),s(x),s(y)) -> mod#(minus(x,y),s(y)) p7: 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: pred(s(x)) -> x r5: minus(x,|0|()) -> x r6: minus(x,s(y)) -> pred(minus(x,y)) r7: mod(|0|(),y) -> |0|() r8: mod(s(x),|0|()) -> |0|() r9: mod(s(x),s(y)) -> if_mod(le(y,x),s(x),s(y)) r10: if_mod(true(),s(x),s(y)) -> mod(minus(x,y),s(y)) r11: if_mod(false(),s(x),s(y)) -> s(x) The estimated dependency graph contains the following SCCs: {p4, p6} {p1} {p3} -- 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: pred(s(x)) -> x r5: minus(x,|0|()) -> x r6: minus(x,s(y)) -> pred(minus(x,y)) r7: mod(|0|(),y) -> |0|() r8: mod(s(x),|0|()) -> |0|() r9: mod(s(x),s(y)) -> if_mod(le(y,x),s(x),s(y)) r10: if_mod(true(),s(x),s(y)) -> mod(minus(x,y),s(y)) r11: if_mod(false(),s(x),s(y)) -> s(x) The set of usable rules consists of r4, r5, r6 Take the reduction pair: generalized weighted path order (>=MG, >G) base order 1: max/plus interpretation on natural numbers: if_mod#_A(x1,x2,x3) = max{14, x2, x3 + 10} true_A = 4 s_A(x1) = x1 + 8 mod#_A(x1,x2) = max{18, x1, x2 + 10} minus_A(x1,x2) = x1 + 8 le_A(x1,x2) = max{x1 + 19, x2 + 5} pred_A(x1) = max{7, x1 - 7} |0|_A = 5 base order 2: marked-algebra reduction triple (>=A, >=A!, >A!): matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: if_mod#_A(x1,x2,x3) = 0 true_A() = 2 s_A(x1) = x1 + 1 mod#_A(x1,x2) = 0 minus_A(x1,x2) = x1 + 3 le_A(x1,x2) = 1 pred_A(x1) = x1 |0|_A() = 2 if_mod#!_A(x1,x2,x3) = 5 true!_A() = 6 s!_A(x1) = 5 mod#!_A(x1,x2) = 5 minus!_A(x1,x2) = 2 le!_A(x1,x2) = 3 pred!_A(x1) = x1 + 3 |0|!_A() = 1 partial status: pi(if_mod#) = [2] pi(true) = [] pi(s) = [] pi(mod#) = [1] pi(minus) = [1] pi(le) = [1, 2] pi(pred) = [] pi(|0|) = [] 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: pred(s(x)) -> x r5: minus(x,|0|()) -> x r6: minus(x,s(y)) -> pred(minus(x,y)) r7: mod(|0|(),y) -> |0|() r8: mod(s(x),|0|()) -> |0|() r9: mod(s(x),s(y)) -> if_mod(le(y,x),s(x),s(y)) r10: if_mod(true(),s(x),s(y)) -> mod(minus(x,y),s(y)) r11: 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: pred(s(x)) -> x r5: minus(x,|0|()) -> x r6: minus(x,s(y)) -> pred(minus(x,y)) r7: mod(|0|(),y) -> |0|() r8: mod(s(x),|0|()) -> |0|() r9: mod(s(x),s(y)) -> if_mod(le(y,x),s(x),s(y)) r10: if_mod(true(),s(x),s(y)) -> mod(minus(x,y),s(y)) r11: if_mod(false(),s(x),s(y)) -> s(x) The set of usable rules consists of (no rules) Take the reduction pair: generalized weighted path order (>=MG, >G) base order 1: max/plus interpretation on natural numbers: le#_A(x1,x2) = max{8, x2} s_A(x1) = x1 + 14 base order 2: 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) = 0 s_A(x1) = 1 le#!_A(x1,x2) = x2 + 3 s!_A(x1) = x1 + 3 partial status: pi(le#) = [] 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: minus#(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: pred(s(x)) -> x r5: minus(x,|0|()) -> x r6: minus(x,s(y)) -> pred(minus(x,y)) r7: mod(|0|(),y) -> |0|() r8: mod(s(x),|0|()) -> |0|() r9: mod(s(x),s(y)) -> if_mod(le(y,x),s(x),s(y)) r10: if_mod(true(),s(x),s(y)) -> mod(minus(x,y),s(y)) r11: if_mod(false(),s(x),s(y)) -> s(x) The set of usable rules consists of r7 Take the reduction pair: generalized weighted path order (>=MG, >G) base order 1: max/plus interpretation on natural numbers: minus#_A(x1,x2) = max{3, x2 - 3} s_A(x1) = x1 + 11 mod_A(x1,x2) = max{13, x2 + 6} |0|_A = 10 base order 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) = x2 s_A(x1) = x1 + 1 mod_A(x1,x2) = x1 |0|_A() = 2 minus#!_A(x1,x2) = 0 s!_A(x1) = 1 mod!_A(x1,x2) = x1 + x2 |0|!_A() = 7 partial status: pi(minus#) = [] pi(s) = [1] pi(mod) = [] pi(|0|) = [] The following rules are removed: p1 Then no dependency pair remains.