YES We show the termination of the TRS R: f(|0|()) -> s(|0|()) f(s(|0|())) -> s(|0|()) f(s(s(x))) -> f(f(s(x))) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: f#(s(s(x))) -> f#(f(s(x))) p2: f#(s(s(x))) -> f#(s(x)) and R consists of: r1: f(|0|()) -> s(|0|()) r2: f(s(|0|())) -> s(|0|()) r3: f(s(s(x))) -> f(f(s(x))) 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(s(x))) -> f#(f(s(x))) p2: f#(s(s(x))) -> f#(s(x)) and R consists of: r1: f(|0|()) -> s(|0|()) r2: f(s(|0|())) -> s(|0|()) r3: f(s(s(x))) -> f(f(s(x))) The set of usable rules consists of r1, r2, r3 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: model-based reduction triple (=A, >=A!, >A!): finite algebra: carrier: {0,1} interpretations: f#_A(0) = 0 f#_A(1) = 0 s_A(0) = 1 s_A(1) = 0 f_A(0) = 0 f_A(1) = 0 |0|_A = 1 f#!_A(0) = 0 f#!_A(1) = 0 s!_A(0) = 1 s!_A(1) = 1 f!_A(0) = 1 f!_A(1) = 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(s(x))) -> f#(f(s(x))) and R consists of: r1: f(|0|()) -> s(|0|()) r2: f(s(|0|())) -> s(|0|()) r3: f(s(s(x))) -> f(f(s(x))) 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(s(x))) -> f#(f(s(x))) and R consists of: r1: f(|0|()) -> s(|0|()) r2: f(s(|0|())) -> s(|0|()) r3: f(s(s(x))) -> f(f(s(x))) The set of usable rules consists of r1, r2, r3 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: model-based reduction triple (=A, >=A!, >A!): finite algebra: carrier: {0,1} interpretations: f#_A(0) = 0 f#_A(1) = 0 s_A(0) = 0 s_A(1) = 0 f_A(0) = 0 f_A(1) = 0 |0|_A = 1 f#!_A(0) = 1 f#!_A(1) = 0 s!_A(0) = 1 s!_A(1) = 0 f!_A(0) = 0 f!_A(1) = 1 |0|!_A = 0 partial status: pi(f#) = [1] pi(s) = [1] pi(f) = [1] pi(|0|) = [] The following rules are removed: p1 Then no dependency pair remains.