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: weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: f#_A(x1,x2) = x1 + ((1,0),(1,1)) x2 + (2,1) g_A(x1) = ((1,0),(1,1)) x1 + (1,0) b_A() = (3,3) a_A() = (2,1) c_A() = (0,0) precedence: f# = b > g = a = c partial status: pi(f#) = [] pi(g) = [] pi(b) = [] pi(a) = [] pi(c) = [] The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains.