Consider the TRS R consisting of the rewrite rules 1: pred(s(x)) -> x 2: minus(x,0) -> x 3: minus(x,s(y)) -> pred(minus(x,y)) 4: quot(0,s(y)) -> 0 5: quot(s(x),s(y)) -> s(quot(minus(x,y),s(y))) There are 4 dependency pairs: 6: MINUS(x,s(y)) -> PRED(minus(x,y)) 7: MINUS(x,s(y)) -> MINUS(x,y) 8: QUOT(s(x),s(y)) -> QUOT(minus(x,y),s(y)) 9: QUOT(s(x),s(y)) -> MINUS(x,y) The approximated dependency graph contains 2 SCCs: {7} and {8}. - Consider the SCC {7}. There are no usable rules. By taking the polynomial interpretation [s](x) = x + 1 and [MINUS](x,y) = x + y + 1, rule 7 is strictly decreasing. - Consider the SCC {8}. The usable rules are {1-3}. By taking the polynomial interpretation [0] = 1, [minus](x,y) = [pred](x) = x, [s](x) = x + 1 and [QUOT](x,y) = x + y + 1, the rules in {2,3} are weakly decreasing and the rules in {1,8} are strictly decreasing. Hence the TRS is terminating.