Prove that every Non-Empty set of Positive Integers contains a "Least Element".
(In reply to
{P, r, o, o, f} by Brian Smith)
The proof doesn't work.
Imagine that the problem referred to all integers rather than positive ones. Your proof does not use the fact that all the integers are positive. However, it is not the case that every set of integers has a least value. The set of even integers is one counterexample.