YES We show the termination of the TRS R: f(g(x,y),f(y,y)) -> f(g(y,x),y) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: f#(g(x,y),f(y,y)) -> f#(g(y,x),y) and R consists of: r1: f(g(x,y),f(y,y)) -> f(g(y,x),y) The estimated dependency graph contains the following SCCs: {p1} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: f#(g(x,y),f(y,y)) -> f#(g(y,x),y) and R consists of: r1: f(g(x,y),f(y,y)) -> f(g(y,x),y) The set of usable rules consists of (no rules) Take the reduction pair: matrix interpretations: carrier: N^3 order: lexicographic order interpretations: f#_A(x1,x2) = ((1,0,0),(0,1,0),(1,0,1)) x1 + ((0,0,0),(0,0,0),(1,0,0)) x2 g_A(x1,x2) = ((0,0,0),(1,0,0),(0,0,0)) x1 + ((0,0,0),(1,0,0),(0,0,0)) x2 f_A(x1,x2) = ((0,0,0),(0,0,0),(1,0,0)) x1 + ((1,0,0),(1,0,0),(0,1,0)) x2 + (1,1,1) The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains.