Injective and Surjective Functions
If $g(f(x))$ is one-to-one (injective) show $f(x)$ is also one-to-one given that $f$ is a function from $A$ to $B$ and $g$ a function from $B$ to $C$.
I've just started my Discrete math course and I'd like some help on this. I'm pretty sure we're supposed to use set theory laws to prove this.
So far I know the three conditions that satisfy an injective function (sorry, having difficulties typing all this TeX markup so I'll skip that).