Consider the TRS R consisting of the rewrite rules 1: f(j(x,y),y) -> g(f(x,k(y))) 2: f(x,h1(y,z)) -> h2(0,x,h1(y,z)) 3: g(h2(x,y,h1(z,u))) -> h2(s(x),y,h1(z,u)) 4: h2(x,j(y,h1(z,u)),h1(z,u)) -> h2(s(x),y,h1(s(z),u)) 5: i(f(x,h(y))) -> y 6: i(h2(s(x),y,h1(x,z))) -> z 7: k(h(x)) -> h1(0,x) 8: k(h1(x,y)) -> h1(s(x),y) There are 6 dependency pairs: 9: F(j(x,y),y) -> G(f(x,k(y))) 10: F(j(x,y),y) -> F(x,k(y)) 11: F(j(x,y),y) -> K(y) 12: F(x,h1(y,z)) -> H2(0,x,h1(y,z)) 13: G(h2(x,y,h1(z,u))) -> H2(s(x),y,h1(z,u)) 14: H2(x,j(y,h1(z,u)),h1(z,u)) -> H2(s(x),y,h1(s(z),u)) The approximated dependency graph contains 2 SCCs: {14} and {10}. - Consider the SCC {14}. There are no usable rules. By taking the polynomial interpretation [s](x) = x, [h1](x,y) = [j](x,y) = x + y + 1 and [H2](x,y,z) = x + y + z + 1, rule 14 is strictly decreasing. - Consider the SCC {10}. The usable rules are {7,8}. By taking the polynomial interpretation [0] = 1, [F](x,y) = [h](x) = [k](x) = [s](x) = x + 1 and [h1](x,y) = [j](x,y) = x + y + 1, the rules in {7,8} are weakly decreasing and rule 10 is strictly decreasing. Hence the TRS is terminating.