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)) -- 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) 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)) The estimated dependency graph contains the following SCCs: {p2} {p1, p5} {p4} -- 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)) The set of usable rules consists of r1, r2, r7 Take the reduction pair: generalized weighted path order (>=MG, >G) base order 1: matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: quot#_A(x1,x2) = x1 + x2 s_A(x1) = x1 + 2 minus_A(x1,x2) = x1 + 1 |0|_A() = 1 plus_A(x1,x2) = x2 + 3 base order 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() = 1 plus_A(x1,x2) = x2 + 2 quot#!_A(x1,x2) = x2 s!_A(x1) = x1 + 4 minus!_A(x1,x2) = x1 + 3 |0|!_A() = 0 plus!_A(x1,x2) = 5 partial status: pi(quot#) = [] pi(s) = [] pi(minus) = [] pi(|0|) = [] pi(plus) = [] 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)) The set of usable rules consists of r1, r5, r6 Take the reduction pair: generalized weighted path order (>=MG, >G) base order 1: matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: minus#_A(x1,x2) = x1 + x2 + 3 s_A(x1) = x1 + 2 minus_A(x1,x2) = x1 + x2 + 4 plus_A(x1,x2) = x1 + x2 + 3 |0|_A() = 1 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) = x1 + x2 s_A(x1) = x1 + 1 minus_A(x1,x2) = x1 + x2 + 6 plus_A(x1,x2) = x1 + x2 + 1 |0|_A() = 1 minus#!_A(x1,x2) = x1 + x2 + 5 s!_A(x1) = x1 + 6 minus!_A(x1,x2) = x1 + x2 + 3 plus!_A(x1,x2) = x1 + x2 + 10 |0|!_A() = 3 partial status: pi(minus#) = [] pi(s) = [1] pi(minus) = [1, 2] pi(plus) = [] pi(|0|) = [] 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: 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)) The set of usable rules consists of r1, r3 Take the reduction pair: generalized weighted path order (>=MG, >G) base order 1: matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: plus#_A(x1,x2) = x1 + x2 + 2 s_A(x1) = x1 + 1 minus_A(x1,x2) = x1 + 2 |0|_A() = 0 quot_A(x1,x2) = x2 base order 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() = 1 quot_A(x1,x2) = x1 plus#!_A(x1,x2) = x1 + x2 s!_A(x1) = x1 + 2 minus!_A(x1,x2) = x1 + x2 + 3 |0|!_A() = 3 quot!_A(x1,x2) = x2 partial status: pi(plus#) = [2] pi(s) = [] pi(minus) = [] pi(|0|) = [] pi(quot) = [] The following rules are removed: p1 Then no dependency pair remains.