YES We show the termination of the TRS R: g(s(x)) -> f(x) f(|0|()) -> s(|0|()) f(s(x)) -> s(s(g(x))) g(|0|()) -> |0|() -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: g#(s(x)) -> f#(x) p2: f#(s(x)) -> g#(x) and R consists of: r1: g(s(x)) -> f(x) r2: f(|0|()) -> s(|0|()) r3: f(s(x)) -> s(s(g(x))) r4: g(|0|()) -> |0|() The estimated dependency graph contains the following SCCs: {p1, p2} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: g#(s(x)) -> f#(x) p2: f#(s(x)) -> g#(x) and R consists of: r1: g(s(x)) -> f(x) r2: f(|0|()) -> s(|0|()) r3: f(s(x)) -> s(s(g(x))) r4: g(|0|()) -> |0|() The set of usable rules consists of (no rules) 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: g#_A(x1) = x1 s_A(x1) = x1 + 3 f#_A(x1) = x1 base order 2: marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: g#_A(x1) = max{0, x1 - 13} s_A(x1) = max{12, x1 + 6} f#_A(x1) = max{0, x1 - 13} g#!_A(x1) = max{2, x1 - 13} s!_A(x1) = max{4, x1 - 9} f#!_A(x1) = max{1, x1 - 9} partial status: pi(g#) = [] pi(s) = [1] pi(f#) = [1] The following rules are removed: p1, p2 Then no dependency pair remains.