YES We show the termination of the TRS R: p(a(x0),p(a(a(a(x1))),x2)) -> p(a(x2),p(a(a(b(x0))),x2)) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: p#(a(x0),p(a(a(a(x1))),x2)) -> p#(a(x2),p(a(a(b(x0))),x2)) p2: p#(a(x0),p(a(a(a(x1))),x2)) -> p#(a(a(b(x0))),x2) and R consists of: r1: p(a(x0),p(a(a(a(x1))),x2)) -> p(a(x2),p(a(a(b(x0))),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(a(a(x1))),x2)) -> p#(a(a(b(x0))),x2) and R consists of: r1: p(a(x0),p(a(a(a(x1))),x2)) -> p(a(x2),p(a(a(b(x0))),x2)) The set of usable rules consists of (no rules) Take the reduction pair: lexicographic combination of reduction pairs: 1. matrix interpretations: carrier: N^1 order: standard order interpretations: p#_A(x1,x2) = x1 + x2 a_A(x1) = x1 + 1 p_A(x1,x2) = x2 + 2 b_A(x1) = x1 2. lexicographic path order with precedence: precedence: b > p > p# > a argument filter: pi(p#) = [1, 2] pi(a) = [] pi(p) = [2] pi(b) = [1] The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains.