YES We show the termination of the TRS R: -(-(neg(x),neg(x)),-(neg(y),neg(y))) -> -(-(x,y),-(x,y)) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: -#(-(neg(x),neg(x)),-(neg(y),neg(y))) -> -#(-(x,y),-(x,y)) p2: -#(-(neg(x),neg(x)),-(neg(y),neg(y))) -> -#(x,y) and R consists of: r1: -(-(neg(x),neg(x)),-(neg(y),neg(y))) -> -(-(x,y),-(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: -#(-(neg(x),neg(x)),-(neg(y),neg(y))) -> -#(-(x,y),-(x,y)) p2: -#(-(neg(x),neg(x)),-(neg(y),neg(y))) -> -#(x,y) and R consists of: r1: -(-(neg(x),neg(x)),-(neg(y),neg(y))) -> -(-(x,y),-(x,y)) The set of usable rules consists of r1 Take the reduction pair: lexicographic combination of reduction pairs: 1. lexicographic path order with precedence: precedence: -# > - > neg argument filter: pi(-#) = 1 pi(-) = 1 pi(neg) = 1 2. lexicographic path order with precedence: precedence: - > -# > neg argument filter: pi(-#) = [1] pi(-) = [1] pi(neg) = [1] The next rules are strictly ordered: p1, p2 We remove them from the problem. Then no dependency pair remains.