Consider the TRS R consisting of the rewrite rules 1: admit(x,nil) -> nil 2: admit(x,u . (v . (w . z))) -> cond(sum(x,u,v) = w,u . (v . (w . admit(carry(x,u,v),z)))) 3: cond(true,y) -> y There are 2 dependency pairs: 4: ADMIT(x,u . (v . (w . z))) -> COND(sum(x,u,v) = w,u . (v . (w . admit(carry(x,u,v),z)))) 5: ADMIT(x,u . (v . (w . z))) -> ADMIT(carry(x,u,v),z) The approximated dependency graph contains one SCC: {5}. - Consider the SCC {5}. There are no usable rules. By taking the polynomial interpretation [w] = 1, [.](x,y) = [ADMIT](x,y) = x + y + 1 and [carry](x,y,z) = x + y + z + 1, rule 5 is strictly decreasing. Hence the TRS is terminating.