I have a question regarding this.(adsbygoogle = window.adsbygoogle || []).push({});

I wish I were home right now so I can give the exact words.

Anyways, the book is talking about continuous maps from one space to another. This is basically what it says...

Let f be a function with domain D in R. Then the following statements are equivalent:

f is continuous

If D is open, then the inverse image of every open set under f is again open.

If D is closed, then the inverse image of every closed set under f is again closed.

There are others, but that's not important.

I just want to clarify that f does not need to be one-to-one, correct?

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# Continous Mappings (Functions)

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