Consider the TRS R consisting of the rewrite rules 1: f(0) -> true 2: f(1) -> false 3: f(s(x)) -> f(x) 4: if(true,x,y) -> x 5: if(false,x,y) -> y 6: g(s(x),s(y)) -> if(f(x),s(x),s(y)) 7: g(x,c(y)) -> g(x,g(s(c(y)),y)) There are 5 dependency pairs: 8: F(s(x)) -> F(x) 9: G(s(x),s(y)) -> IF(f(x),s(x),s(y)) 10: G(s(x),s(y)) -> F(x) 11: G(x,c(y)) -> G(x,g(s(c(y)),y)) 12: G(x,c(y)) -> G(s(c(y)),y) The approximated dependency graph contains 2 SCCs: {8} and {11,12}. - Consider the SCC {8}. There are no usable rules. By taking the polynomial interpretation [F](x) = [s](x) = x + 1, rule 8 is strictly decreasing. - Consider the SCC {11,12}. By taking the polynomial interpretation [0] = [1] = [f](x) = [false] = [s](x) = [true] = 1, [c](x) = x + 1, [g](x,y) = [G](x,y) = y + 1 and [if](x,y,z) = y + z, the rules in {1-7,11} are weakly decreasing and rule 12 is strictly decreasing. There is one new SCC. - Consider the SCC {11}. By taking the polynomial interpretation [s](x) = 0, [0] = [1] = [f](x) = [false] = [true] = 1, [c](x) = x + 1, [g](x,y) = x + y, [G](x,y) = x + y + 1 and [if](x,y,z) = y + z, the rules in {1-6} are weakly decreasing and the rules in {7,11} are strictly decreasing. Hence the TRS is terminating.