Consider the TRS R consisting of the rewrite rules 1: x + 0 -> x 2: minus(x) + x -> 0 3: minus(0) -> 0 4: minus(minus(x)) -> x 5: minus(x + y) -> minus(y) + minus(x) 6: x * 1 -> x 7: x * 0 -> 0 8: x * (y + z) -> (x * y) + (x * z) 9: x * minus(y) -> minus(x * y) There are 8 dependency pairs: 10: MINUS(x + y) -> minus(y) +# minus(x) 11: MINUS(x + y) -> MINUS(y) 12: MINUS(x + y) -> MINUS(x) 13: x *# (y + z) -> (x * y) +# (x * z) 14: x *# (y + z) -> x *# y 15: x *# (y + z) -> x *# z 16: x *# minus(y) -> MINUS(x * y) 17: x *# minus(y) -> x *# y The approximated dependency graph contains 2 SCCs: {11,12} and {14,15,17}. - Consider the SCC {11,12}. There are no usable rules. By taking the polynomial interpretation [MINUS](x) = x + 1 and [+](x,y) = x + y + 1, the rules in {11,12} are strictly decreasing. - Consider the SCC {14,15,17}. There are no usable rules. By taking the polynomial interpretation [minus](x) = x + 1 and [*#](x,y) = [+](x,y) = x + y + 1, the rules in {14,15,17} are strictly decreasing. Hence the TRS is terminating.