Consider the TRS R consisting of the rewrite rules 1: xor(x,F) -> x 2: xor(x,neg(x)) -> F 3: and(x,T) -> x 4: and(x,F) -> F 5: and(x,x) -> x 6: and(xor(x,y),z) -> xor(and(x,z),and(y,z)) 7: xor(x,x) -> F 8: impl(x,y) -> xor(and(x,y),xor(x,T)) 9: or(x,y) -> xor(and(x,y),xor(x,y)) 10: equiv(x,y) -> xor(x,xor(y,T)) 11: neg(x) -> xor(x,T) There are 12 dependency pairs: 12: AND(xor(x,y),z) -> XOR(and(x,z),and(y,z)) 13: AND(xor(x,y),z) -> AND(x,z) 14: AND(xor(x,y),z) -> AND(y,z) 15: IMPL(x,y) -> XOR(and(x,y),xor(x,T)) 16: IMPL(x,y) -> AND(x,y) 17: IMPL(x,y) -> XOR(x,T) 18: OR(x,y) -> XOR(and(x,y),xor(x,y)) 19: OR(x,y) -> AND(x,y) 20: OR(x,y) -> XOR(x,y) 21: EQUIV(x,y) -> XOR(x,xor(y,T)) 22: EQUIV(x,y) -> XOR(y,T) 23: NEG(x) -> XOR(x,T) The approximated dependency graph contains one SCC: {13,14}. - Consider the SCC {13,14}. There are no usable rules. By taking the polynomial interpretation [AND](x,y) = [xor](x,y) = x + y + 1, the rules in {13,14} are strictly decreasing. Hence the TRS is terminating.