YES We show the termination of the TRS R: a() -> g(c()) g(a()) -> b() f(g(X),b()) -> f(a(),X) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: a#() -> g#(c()) p2: f#(g(X),b()) -> f#(a(),X) p3: f#(g(X),b()) -> a#() and R consists of: r1: a() -> g(c()) r2: g(a()) -> b() r3: f(g(X),b()) -> f(a(),X) The estimated dependency graph contains the following SCCs: {p2} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: f#(g(X),b()) -> f#(a(),X) and R consists of: r1: a() -> g(c()) r2: g(a()) -> b() r3: f(g(X),b()) -> f(a(),X) The set of usable rules consists of r1 Take the reduction pair: lexicographic combination of reduction pairs: 1. weighted path order base order: max/plus interpretations on natural numbers: f#_A(x1,x2) = max{7, x1 + 3, x2 + 2} g_A(x1) = max{2, x1 + 1} b_A = 6 a_A = 3 c_A = 1 precedence: f# > g = b = a = c partial status: pi(f#) = [1, 2] pi(g) = [1] pi(b) = [] pi(a) = [] pi(c) = [] 2. weighted path order base order: max/plus interpretations on natural numbers: f#_A(x1,x2) = max{x1 - 1, x2 + 2} g_A(x1) = x1 b_A = 2 a_A = 3 c_A = 4 precedence: f# = g = b = a = c partial status: pi(f#) = [] pi(g) = [1] pi(b) = [] pi(a) = [] pi(c) = [] The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains.