Consider the TRS R consisting of the rewrite rules 1: x + 0 -> x 2: x + i(x) -> 0 3: (x + y) + z -> x + (y + z) 4: x * (y + z) -> (x * y) + (x * z) 5: (x + y) * z -> (x * z) + (y * z) There are 8 dependency pairs: 6: (x + y) +# z -> x +# (y + z) 7: (x + y) +# z -> y +# z 8: x *# (y + z) -> (x * y) +# (x * z) 9: x *# (y + z) -> x *# y 10: x *# (y + z) -> x *# z 11: (x + y) *# z -> (x * z) +# (y * z) 12: (x + y) *# z -> x *# z 13: (x + y) *# z -> y *# z The approximated dependency graph contains 2 SCCs: {6,7} and {9,10,12,13}. - Consider the SCC {6,7}. The usable rules are {1-3}. By taking the polynomial interpretation [0] = 1, [i](x) = x + 1 and [+](x,y) = [+#](x,y) = x + y + 1, the rules in {3,6} are weakly decreasing and the rules in {1,2,7} are strictly decreasing. There is one new SCC. - Consider the SCC {6}. By taking the polynomial interpretation [0] = 1, [+#](x,y) = [i](x) = x + 1 and [+](x,y) = x + y + 1, rule 3 is weakly decreasing and the rules in {1,2,6} are strictly decreasing. - Consider the SCC {9,10,12,13}. There are no usable rules. By taking the polynomial interpretation [*#](x,y) = [+](x,y) = x + y + 1, the rules in {9,10,12,13} are strictly decreasing. Hence the TRS is terminating.