NO Problem: inv(0()) -> 0() inv(s(x)) -> p(inv(x)) inv(p(x)) -> s(inv(x)) minus(x,0()) -> x minus(x,p(y)) -> s(minus(x,y)) minus(x,s(y)) -> p(minus(x,y)) minus(0(),x) -> inv(x) inv(x) -> minus(0(),x) inv(minus(x,y)) -> minus(y,x) s(p(x)) -> x p(s(x)) -> x Proof: Nonconfluence Processor: terms: p(minus(x630,x)) *<- inv(minus(x,p(x630))) ->* minus(p(x630),x) Qed