F is an open mapping implies f inverse cont.

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We have a continuous bijection f:X-->Y.

Prove that if f is open, then f inverse is continuous.


I can't figure it out.
"Proof". For V open in Y, there exists W open in X such that f[W] \subseteq V. Where does the f is open definition apply?
 
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Ah! I got it. Posting always helps the blood get flowing. Trying to explain what I know to others.
 

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