YES We show the termination of the TRS R: f(|0|(),y) -> |0|() f(s(x),y) -> f(f(x,y),y) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: f#(s(x),y) -> f#(f(x,y),y) p2: f#(s(x),y) -> f#(x,y) and R consists of: r1: f(|0|(),y) -> |0|() r2: f(s(x),y) -> f(f(x,y),y) The estimated dependency graph contains the following SCCs: {p1, p2} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: f#(s(x),y) -> f#(f(x,y),y) p2: f#(s(x),y) -> f#(x,y) and R consists of: r1: f(|0|(),y) -> |0|() r2: f(s(x),y) -> f(f(x,y),y) The set of usable rules consists of r1, r2 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: f#_A(x1,x2) = max{0, x1 - 8, x2 - 2} s_A(x1) = max{4, x1} f_A(x1,x2) = max{7, x1 - 8, x2 - 2} |0|_A = 0 f#!_A(x1,x2) = max{x1 - 5, x2 + 3} s!_A(x1) = x1 + 5 f!_A(x1,x2) = 4 |0|!_A = 1 2. marked-algebra reduction triple (>=A, >=A!, >A!): matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: f#_A(x1,x2) = 0 s_A(x1) = x1 + 2 f_A(x1,x2) = x1 + 1 |0|_A() = 1 f#!_A(x1,x2) = x2 + 3 s!_A(x1) = 2 f!_A(x1,x2) = 1 |0|!_A() = 0 partial status: pi(f#) = [1] pi(s) = [1] pi(f) = [1] pi(|0|) = [] The following rules are removed: p2 -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: f#(s(x),y) -> f#(f(x,y),y) and R consists of: r1: f(|0|(),y) -> |0|() r2: f(s(x),y) -> f(f(x,y),y) The estimated dependency graph contains the following SCCs: {p1} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: f#(s(x),y) -> f#(f(x,y),y) and R consists of: r1: f(|0|(),y) -> |0|() r2: f(s(x),y) -> f(f(x,y),y) The set of usable rules consists of r1, r2 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: f#_A(x1,x2) = max{0, x1 - 5, x2 - 1} s_A(x1) = max{3, x1} f_A(x1,x2) = max{1, x1 - 2} |0|_A = 1 f#!_A(x1,x2) = max{6, x1 + 4} s!_A(x1) = 0 f!_A(x1,x2) = max{0, x1 - 4, x2 - 1} |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: f#_A(x1,x2) = x1 s_A(x1) = x1 + 2 f_A(x1,x2) = x1 + 1 |0|_A() = 1 f#!_A(x1,x2) = 2 s!_A(x1) = 3 f!_A(x1,x2) = 1 |0|!_A() = 0 partial status: pi(f#) = [] pi(s) = [1] pi(f) = [] pi(|0|) = [] The following rules are removed: p1 Then no dependency pair remains.