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(|0|(),y) -> y plus(s(x),y) -> s(plus(x,y)) plus(s(x),y) -> plus(x,s(y)) plus(s(x),y) -> s(plus(minus(x,y),double(y))) plus(s(plus(x,y)),z) -> s(plus(plus(x,y),z)) -- 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),y) -> plus#(x,y) p4: plus#(s(x),y) -> plus#(x,s(y)) p5: plus#(s(x),y) -> plus#(minus(x,y),double(y)) p6: plus#(s(x),y) -> minus#(x,y) p7: plus#(s(x),y) -> double#(y) p8: plus#(s(plus(x,y)),z) -> plus#(plus(x,y),z) 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(|0|(),y) -> y r6: plus(s(x),y) -> s(plus(x,y)) r7: plus(s(x),y) -> plus(x,s(y)) r8: plus(s(x),y) -> s(plus(minus(x,y),double(y))) r9: plus(s(plus(x,y)),z) -> s(plus(plus(x,y),z)) The estimated dependency graph contains the following SCCs: {p3, p4, p5, p8} {p1} {p2} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: plus#(s(plus(x,y)),z) -> plus#(plus(x,y),z) p2: plus#(s(x),y) -> plus#(minus(x,y),double(y)) p3: plus#(s(x),y) -> plus#(x,s(y)) p4: 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: double(|0|()) -> |0|() r4: double(s(x)) -> s(s(double(x))) r5: plus(|0|(),y) -> y r6: plus(s(x),y) -> s(plus(x,y)) r7: plus(s(x),y) -> plus(x,s(y)) r8: plus(s(x),y) -> s(plus(minus(x,y),double(y))) r9: plus(s(plus(x,y)),z) -> s(plus(plus(x,y),z)) The set of usable rules consists of r1, r2, r3, r4, r5, r6, r7, r8, r9 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) = x1 s_A(x1) = max{7, x1} plus_A(x1,x2) = max{1, x1, x2} minus_A(x1,x2) = max{3, x1} double_A(x1) = max{2, x1} |0|_A = 3 plus#!_A(x1,x2) = 7 s!_A(x1) = 7 plus!_A(x1,x2) = max{15, x2 + 8} minus!_A(x1,x2) = 1 double!_A(x1) = max{6, x1 + 1} |0|!_A = 5 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) = x2 s_A(x1) = x1 plus_A(x1,x2) = x2 + 1 minus_A(x1,x2) = x1 + x2 + 1 double_A(x1) = x1 |0|_A() = 1 plus#!_A(x1,x2) = 2 s!_A(x1) = 4 plus!_A(x1,x2) = 3 minus!_A(x1,x2) = 1 double!_A(x1) = 1 |0|!_A() = 0 partial status: pi(plus#) = [1] pi(s) = [1] pi(plus) = [1, 2] pi(minus) = [1] pi(double) = [1] pi(|0|) = [] The following rules are removed: p1, p2, p3, p4 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) 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(|0|(),y) -> y r6: plus(s(x),y) -> s(plus(x,y)) r7: plus(s(x),y) -> plus(x,s(y)) r8: plus(s(x),y) -> s(plus(minus(x,y),double(y))) r9: plus(s(plus(x,y)),z) -> s(plus(plus(x,y),z)) 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) = 0 s_A(x1) = max{25, x1 + 19} minus#!_A(x1,x2) = max{5, x2 - 26} s!_A(x1) = max{5, x1 + 1} 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 + 1 minus#!_A(x1,x2) = 2 s!_A(x1) = 2 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(|0|(),y) -> y r6: plus(s(x),y) -> s(plus(x,y)) r7: plus(s(x),y) -> plus(x,s(y)) r8: plus(s(x),y) -> s(plus(minus(x,y),double(y))) r9: plus(s(plus(x,y)),z) -> s(plus(plus(x,y),z)) 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) = 0 s_A(x1) = x1 + 14 double#!_A(x1) = max{0, x1 - 15} s!_A(x1) = max{0, x1 - 3} 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 + 2 s!_A(x1) = x1 + 2 partial status: pi(double#) = [1] pi(s) = [1] The following rules are removed: p1 Then no dependency pair remains.