Constructing Mathematical Statements

[danago]

Hi. I've just started a new maths course and i have come to realize that i have never been taught how to use symbols to write mathematical statements. For example, up until a day ago, i didnt know what $$\exists$$ or $$\forall$$ meant.

Is anybody able to share some links that will explain the use of such symbols to construct statements? I am able to construct really basic statements such as:

"For all x>4 there exists x>5" $$\forall x>4 , \exists x>5$$

But i don't even know if what i have written above is correct, or how to write more complex statements.

Thanks in advance,
Dan.

 

[mrandersdk]

you could take a look at

http://en.wikipedia.org/wiki/First-order_logic

maybe it is a bit too general to really helpfull, look especialy at the sections: Provable identities and Provable inference rules, they are very important.

Since you haven't seen these before i guess they are theaching them to you in the class, and the best way to learn it is really just to use them a lot. Else try to find some basic analysis books they should teach it. I can't say a specific book because the book i learned it from was in danish so it will probably don't help much.