YES We show the termination of the TRS R: f(x,y) -> g(x,y) g(h(x),y) -> h(f(x,y)) g(h(x),y) -> h(g(x,y)) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: f#(x,y) -> g#(x,y) p2: g#(h(x),y) -> f#(x,y) p3: g#(h(x),y) -> g#(x,y) and R consists of: r1: f(x,y) -> g(x,y) r2: g(h(x),y) -> h(f(x,y)) r3: g(h(x),y) -> h(g(x,y)) The estimated dependency graph contains the following SCCs: {p1, p2, p3} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: f#(x,y) -> g#(x,y) p2: g#(h(x),y) -> g#(x,y) p3: g#(h(x),y) -> f#(x,y) and R consists of: r1: f(x,y) -> g(x,y) r2: g(h(x),y) -> h(f(x,y)) r3: g(h(x),y) -> h(g(x,y)) The set of usable rules consists of (no rules) Take the reduction pair: matrix interpretations: carrier: N^4 order: lexicographic order interpretations: f#_A(x1,x2) = ((0,0,0,0),(1,0,0,0),(0,0,0,0),(0,0,0,0)) x1 + x2 + (0,1,1,2) g#_A(x1,x2) = ((0,0,0,0),(1,0,0,0),(0,1,0,0),(1,0,1,0)) x1 + ((1,0,0,0),(0,1,0,0),(0,0,1,0),(0,1,0,1)) x2 h_A(x1) = ((1,0,0,0),(0,0,0,0),(1,1,0,0),(1,1,1,0)) x1 + (1,1,1,1) The next rules are strictly ordered: p1, p2 We remove them from the problem. -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: g#(h(x),y) -> f#(x,y) and R consists of: r1: f(x,y) -> g(x,y) r2: g(h(x),y) -> h(f(x,y)) r3: g(h(x),y) -> h(g(x,y)) The estimated dependency graph contains the following SCCs: (no SCCs)