Hello,

I have a discreet math problem that I cannot figure out. Not even where to start from.

The problem:Let X,Y,Z be non empty sets. Prove that functionf:X->Yisinjectiveif whatever functionsg,h:Z->Xwe get that(f o g) = (f o h)from that follows thatg = h.I know that (f o g), a composition of functions means that it's basicly f(g(x)).

I know that a function is injective iff(x1) == f(x2) -> x1 == x2.How would I go about proving this?

Best regards

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