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))) 6: log(s(0)) -> 0 7: log(s(s(x))) -> s(log(s(quot(x,s(s(0)))))) There are 6 dependency pairs: 8: MINUS(x,s(y)) -> PRED(minus(x,y)) 9: MINUS(x,s(y)) -> MINUS(x,y) 10: QUOT(s(x),s(y)) -> QUOT(minus(x,y),s(y)) 11: QUOT(s(x),s(y)) -> MINUS(x,y) 12: LOG(s(s(x))) -> LOG(s(quot(x,s(s(0))))) 13: LOG(s(s(x))) -> QUOT(x,s(s(0))) The approximated dependency graph contains 3 SCCs: {9}, {10} and {12}. - Consider the SCC {9}. There are no usable rules. By taking the polynomial interpretation [s](x) = x + 1 and [MINUS](x,y) = x + y + 1, rule 9 is strictly decreasing. - Consider the SCC {10}. 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 {1,10} are strictly decreasing. - Consider the SCC {12}. The usable rules are {1-5}. By taking the polynomial interpretation [0] = 1, [minus](x,y) = [pred](x) = [quot](x,y) = x and [LOG](x) = [s](x) = x + 1, the rules in {2-5} are weakly decreasing and the rules in {1,12} are strictly decreasing. Hence the TRS is terminating.