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. weighted path order base order: max/plus interpretations on natural numbers: p#_A(x1,x2) = max{x1 + 10, x2 + 15} a_A(x1) = x1 + 2 p_A(x1,x2) = max{x1 + 3, x2 + 4} b_A(x1) = x1 + 5 precedence: p# = a = p = b partial status: pi(p#) = [1, 2] pi(a) = [1] pi(p) = [1, 2] pi(b) = [1] 2. weighted path order base order: max/plus interpretations on natural numbers: p#_A(x1,x2) = max{x1 - 4, x2 + 2} a_A(x1) = max{6, x1 + 2} p_A(x1,x2) = x2 b_A(x1) = max{4, x1} precedence: p# = a = p = b partial status: pi(p#) = [] 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.