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))) plus(|0|(),y) -> y plus(s(x),y) -> s(plus(x,y)) minus(minus(x,y),z) -> minus(x,plus(y,z)) app(nil(),k) -> k app(l,nil()) -> l app(cons(x,l),k) -> cons(x,app(l,k)) sum(cons(x,nil())) -> cons(x,nil()) sum(cons(x,cons(y,l))) -> sum(cons(plus(x,y),l)) sum(app(l,cons(x,cons(y,k)))) -> sum(app(l,sum(cons(x,cons(y,k))))) -- 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: plus#(s(x),y) -> plus#(x,y) p5: minus#(minus(x,y),z) -> minus#(x,plus(y,z)) p6: minus#(minus(x,y),z) -> plus#(y,z) p7: app#(cons(x,l),k) -> app#(l,k) p8: sum#(cons(x,cons(y,l))) -> sum#(cons(plus(x,y),l)) p9: sum#(cons(x,cons(y,l))) -> plus#(x,y) p10: sum#(app(l,cons(x,cons(y,k)))) -> sum#(app(l,sum(cons(x,cons(y,k))))) p11: sum#(app(l,cons(x,cons(y,k)))) -> app#(l,sum(cons(x,cons(y,k)))) p12: sum#(app(l,cons(x,cons(y,k)))) -> sum#(cons(x,cons(y,k))) 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: plus(|0|(),y) -> y r6: plus(s(x),y) -> s(plus(x,y)) r7: minus(minus(x,y),z) -> minus(x,plus(y,z)) r8: app(nil(),k) -> k r9: app(l,nil()) -> l r10: app(cons(x,l),k) -> cons(x,app(l,k)) r11: sum(cons(x,nil())) -> cons(x,nil()) r12: sum(cons(x,cons(y,l))) -> sum(cons(plus(x,y),l)) r13: sum(app(l,cons(x,cons(y,k)))) -> sum(app(l,sum(cons(x,cons(y,k))))) The estimated dependency graph contains the following SCCs: {p2} {p1, p5} {p10} {p8} {p4} {p7} -- 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: plus(|0|(),y) -> y r6: plus(s(x),y) -> s(plus(x,y)) r7: minus(minus(x,y),z) -> minus(x,plus(y,z)) r8: app(nil(),k) -> k r9: app(l,nil()) -> l r10: app(cons(x,l),k) -> cons(x,app(l,k)) r11: sum(cons(x,nil())) -> cons(x,nil()) r12: sum(cons(x,cons(y,l))) -> sum(cons(plus(x,y),l)) r13: sum(app(l,cons(x,cons(y,k)))) -> sum(app(l,sum(cons(x,cons(y,k))))) The set of usable rules consists of r1, r2, r7, r8 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) = x1 s_A(x1) = x1 + 3 minus_A(x1,x2) = x1 + 1 |0|_A() = 2 plus_A(x1,x2) = x1 + x2 + 6 app_A(x1,x2) = x1 + x2 + 1 nil_A() = 1 quot#!_A(x1,x2) = x1 + x2 s!_A(x1) = x1 + 5 minus!_A(x1,x2) = x1 + 8 |0|!_A() = 8 plus!_A(x1,x2) = 0 app!_A(x1,x2) = 13 nil!_A() = 0 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) = x1 s_A(x1) = x1 + 2 minus_A(x1,x2) = x1 + 1 |0|_A() = 4 plus_A(x1,x2) = x1 + x2 + 2 app_A(x1,x2) = x1 + x2 + 1 nil_A() = 1 quot#!_A(x1,x2) = x2 s!_A(x1) = x1 + 1 minus!_A(x1,x2) = 4 |0|!_A() = 2 plus!_A(x1,x2) = 0 app!_A(x1,x2) = 3 nil!_A() = 0 partial status: pi(quot#) = [2] pi(s) = [1] pi(minus) = [1] pi(|0|) = [] pi(plus) = [] pi(app) = [2] pi(nil) = [] 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: plus(|0|(),y) -> y r6: plus(s(x),y) -> s(plus(x,y)) r7: minus(minus(x,y),z) -> minus(x,plus(y,z)) r8: app(nil(),k) -> k r9: app(l,nil()) -> l r10: app(cons(x,l),k) -> cons(x,app(l,k)) r11: sum(cons(x,nil())) -> cons(x,nil()) r12: sum(cons(x,cons(y,l))) -> sum(cons(plus(x,y),l)) r13: sum(app(l,cons(x,cons(y,k)))) -> sum(app(l,sum(cons(x,cons(y,k))))) The set of usable rules consists of r1, r5, r6, r8 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: minus#_A(x1,x2) = x1 + x2 s_A(x1) = x1 + 1 minus_A(x1,x2) = x1 + x2 + 5 plus_A(x1,x2) = x1 + x2 + 4 |0|_A() = 2 app_A(x1,x2) = x1 + x2 + 1 nil_A() = 1 minus#!_A(x1,x2) = x1 + 1 s!_A(x1) = x1 + 5 minus!_A(x1,x2) = x1 + x2 plus!_A(x1,x2) = x1 + x2 + 9 |0|!_A() = 4 app!_A(x1,x2) = x2 nil!_A() = 0 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 + 8 minus_A(x1,x2) = x1 + x2 + 7 plus_A(x1,x2) = x1 + x2 + 3 |0|_A() = 4 app_A(x1,x2) = x1 + x2 + 1 nil_A() = 1 minus#!_A(x1,x2) = x1 + x2 + 15 s!_A(x1) = x1 + 14 minus!_A(x1,x2) = x1 + x2 plus!_A(x1,x2) = x1 + 23 |0|!_A() = 13 app!_A(x1,x2) = x1 + x2 nil!_A() = 0 partial status: pi(minus#) = [1] pi(s) = [1] pi(minus) = [1] pi(plus) = [2] pi(|0|) = [] pi(app) = [2] pi(nil) = [] 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: sum#(app(l,cons(x,cons(y,k)))) -> sum#(app(l,sum(cons(x,cons(y,k))))) 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: plus(|0|(),y) -> y r6: plus(s(x),y) -> s(plus(x,y)) r7: minus(minus(x,y),z) -> minus(x,plus(y,z)) r8: app(nil(),k) -> k r9: app(l,nil()) -> l r10: app(cons(x,l),k) -> cons(x,app(l,k)) r11: sum(cons(x,nil())) -> cons(x,nil()) r12: sum(cons(x,cons(y,l))) -> sum(cons(plus(x,y),l)) r13: sum(app(l,cons(x,cons(y,k)))) -> sum(app(l,sum(cons(x,cons(y,k))))) The set of usable rules consists of r5, r6, r8, r9, r10, r11, 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!): matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: sum#_A(x1) = 0 app_A(x1,x2) = x1 + x2 + 1 cons_A(x1,x2) = 2 sum_A(x1) = 3 plus_A(x1,x2) = x1 + x2 + 4 |0|_A() = 2 s_A(x1) = x1 + 5 nil_A() = 1 sum#!_A(x1) = x1 + 7 app!_A(x1,x2) = x1 + 12 cons!_A(x1,x2) = 13 sum!_A(x1) = 11 plus!_A(x1,x2) = 10 |0|!_A() = 0 s!_A(x1) = 9 nil!_A() = 10 2. marked-algebra reduction triple (>=A, >=A!, >A!): matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: sum#_A(x1) = 0 app_A(x1,x2) = x1 + x2 cons_A(x1,x2) = x2 + 5 sum_A(x1) = 8 plus_A(x1,x2) = x1 + x2 + 3 |0|_A() = 2 s_A(x1) = 1 nil_A() = 1 sum#!_A(x1) = x1 + 4 app!_A(x1,x2) = x1 + x2 + 7 cons!_A(x1,x2) = x2 + 11 sum!_A(x1) = x1 plus!_A(x1,x2) = 9 |0|!_A() = 0 s!_A(x1) = 1 nil!_A() = 5 partial status: pi(sum#) = [1] pi(app) = [1, 2] pi(cons) = [] pi(sum) = [1] pi(plus) = [2] pi(|0|) = [] pi(s) = [] pi(nil) = [] 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: sum#(cons(x,cons(y,l))) -> sum#(cons(plus(x,y),l)) 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: plus(|0|(),y) -> y r6: plus(s(x),y) -> s(plus(x,y)) r7: minus(minus(x,y),z) -> minus(x,plus(y,z)) r8: app(nil(),k) -> k r9: app(l,nil()) -> l r10: app(cons(x,l),k) -> cons(x,app(l,k)) r11: sum(cons(x,nil())) -> cons(x,nil()) r12: sum(cons(x,cons(y,l))) -> sum(cons(plus(x,y),l)) r13: sum(app(l,cons(x,cons(y,k)))) -> sum(app(l,sum(cons(x,cons(y,k))))) The set of usable rules consists of r1, r5, 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!): matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: sum#_A(x1) = x1 cons_A(x1,x2) = x1 + x2 + 10 plus_A(x1,x2) = x1 + x2 + 4 minus_A(x1,x2) = x1 + x2 + 3 |0|_A() = 2 s_A(x1) = 1 sum#!_A(x1) = x1 + 6 cons!_A(x1,x2) = x1 + 21 plus!_A(x1,x2) = x2 + 27 minus!_A(x1,x2) = x1 + x2 + 3 |0|!_A() = 0 s!_A(x1) = 2 2. marked-algebra reduction triple (>=A, >=A!, >A!): matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: sum#_A(x1) = x1 cons_A(x1,x2) = x1 + x2 + 4 plus_A(x1,x2) = x1 + x2 + 3 minus_A(x1,x2) = x1 + x2 + 2 |0|_A() = 2 s_A(x1) = 1 sum#!_A(x1) = 5 cons!_A(x1,x2) = x2 + 6 plus!_A(x1,x2) = 4 minus!_A(x1,x2) = x1 + x2 |0|!_A() = 0 s!_A(x1) = x1 + 3 partial status: pi(sum#) = [1] pi(cons) = [] pi(plus) = [1, 2] pi(minus) = [1] pi(|0|) = [] 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: plus#(s(x),y) -> plus#(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: plus(|0|(),y) -> y r6: plus(s(x),y) -> s(plus(x,y)) r7: minus(minus(x,y),z) -> minus(x,plus(y,z)) r8: app(nil(),k) -> k r9: app(l,nil()) -> l r10: app(cons(x,l),k) -> cons(x,app(l,k)) r11: sum(cons(x,nil())) -> cons(x,nil()) r12: sum(cons(x,cons(y,l))) -> sum(cons(plus(x,y),l)) r13: sum(app(l,cons(x,cons(y,k)))) -> sum(app(l,sum(cons(x,cons(y,k))))) 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!): matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: plus#_A(x1,x2) = x1 s_A(x1) = x1 + 1 minus_A(x1,x2) = x1 + x2 + 3 |0|_A() = 2 plus#!_A(x1,x2) = x1 + 4 s!_A(x1) = 3 minus!_A(x1,x2) = x1 + x2 + 2 |0|!_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) = x1 s_A(x1) = x1 + 1 minus_A(x1,x2) = x1 + x2 + 2 |0|_A() = 2 plus#!_A(x1,x2) = 2 s!_A(x1) = x1 + 1 minus!_A(x1,x2) = x1 + x2 + 2 |0|!_A() = 0 partial status: pi(plus#) = [1] pi(s) = [1] pi(minus) = [1, 2] pi(|0|) = [] 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: app#(cons(x,l),k) -> app#(l,k) 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: plus(|0|(),y) -> y r6: plus(s(x),y) -> s(plus(x,y)) r7: minus(minus(x,y),z) -> minus(x,plus(y,z)) r8: app(nil(),k) -> k r9: app(l,nil()) -> l r10: app(cons(x,l),k) -> cons(x,app(l,k)) r11: sum(cons(x,nil())) -> cons(x,nil()) r12: sum(cons(x,cons(y,l))) -> sum(cons(plus(x,y),l)) r13: sum(app(l,cons(x,cons(y,k)))) -> sum(app(l,sum(cons(x,cons(y,k))))) 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!): matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: app#_A(x1,x2) = x1 cons_A(x1,x2) = x1 + x2 + 9 app#!_A(x1,x2) = x1 + 18 cons!_A(x1,x2) = x1 + x2 + 17 2. marked-algebra reduction triple (>=A, >=A!, >A!): matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: app#_A(x1,x2) = x1 cons_A(x1,x2) = x1 + x2 + 2 app#!_A(x1,x2) = x1 + 2 cons!_A(x1,x2) = x1 + x2 + 1 partial status: pi(app#) = [] pi(cons) = [] The following rules are removed: p1 Then no dependency pair remains.