YES We show the termination of the TRS R: f(c(s(x),y)) -> f(c(x,s(y))) g(c(x,s(y))) -> g(c(s(x),y)) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: f#(c(s(x),y)) -> f#(c(x,s(y))) p2: g#(c(x,s(y))) -> g#(c(s(x),y)) and R consists of: r1: f(c(s(x),y)) -> f(c(x,s(y))) r2: g(c(x,s(y))) -> g(c(s(x),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#(c(s(x),y)) -> f#(c(x,s(y))) and R consists of: r1: f(c(s(x),y)) -> f(c(x,s(y))) r2: g(c(x,s(y))) -> g(c(s(x),y)) The set of usable rules consists of (no rules) Take the reduction pair: weighted path order base order: max/plus interpretations on natural numbers: f#_A(x1) = x1 + 2 c_A(x1,x2) = max{0, x1 - 6} s_A(x1) = max{9, x1 + 3} precedence: f# = c = s partial status: pi(f#) = [1] pi(c) = [] pi(s) = [1] The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains. -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: g#(c(x,s(y))) -> g#(c(s(x),y)) and R consists of: r1: f(c(s(x),y)) -> f(c(x,s(y))) r2: g(c(x,s(y))) -> g(c(s(x),y)) The set of usable rules consists of (no rules) Take the reduction pair: weighted path order base order: max/plus interpretations on natural numbers: g#_A(x1) = x1 c_A(x1,x2) = max{1, x2 - 2} s_A(x1) = max{4, x1 + 1} precedence: g# = c = s partial status: pi(g#) = [1] pi(c) = [] pi(s) = [1] The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains.