YES We show the termination of the TRS R: p(a(x0),p(a(b(x1)),x2)) -> p(a(b(a(x2))),p(a(a(x1)),x2)) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: p#(a(x0),p(a(b(x1)),x2)) -> p#(a(b(a(x2))),p(a(a(x1)),x2)) p2: p#(a(x0),p(a(b(x1)),x2)) -> p#(a(a(x1)),x2) and R consists of: r1: p(a(x0),p(a(b(x1)),x2)) -> p(a(b(a(x2))),p(a(a(x1)),x2)) The estimated dependency graph contains the following SCCs: {p2} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: p#(a(x0),p(a(b(x1)),x2)) -> p#(a(a(x1)),x2) and R consists of: r1: p(a(x0),p(a(b(x1)),x2)) -> p(a(b(a(x2))),p(a(a(x1)),x2)) The set of usable rules consists of (no rules) Take the reduction pair: lexicographic combination of reduction pairs: 1. lexicographic path order with precedence: precedence: a > p# > b > p argument filter: pi(p#) = 2 pi(a) = [1] pi(p) = [1, 2] pi(b) = 1 2. lexicographic path order with precedence: precedence: p# > a > b > p argument filter: pi(p#) = 2 pi(a) = 1 pi(p) = 2 pi(b) = [1] The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains.