Q:

Proving that $A - B \ne \emptyset$ when $|A| > |B|$?

I am struggling to prove what seems like a trivial fact - subtracting a smaller set from a bigger set cannot produce the empty set - and it just seems like there must be a simple proof of this.
Is there a way to prove that if $|A| > |B|$, then $A - B \ne \emptyset$?
Thanks!

A:

If $A\setminus B = \varnothing$, then $A \subseteq B$ so inclusion provides an injection from $A$ into $B$ implying $\lvert A \rvert \leq \lvert B \rvert$. 

