Discrete Math Help for Sarah | Physics Forum

[sarah22]

Dear "Physics Forum",

Hello! I'm Sarah. Yeah, I'm new here and starting to love this forum. I'm having a hard time proving if a statement is true or false in discrete math. For example, For all X, there's a Y (x+y=x). This question is easy and the answer is true by letting y as 0 and x for anything. But I really get confuse when the question is so complicated like making not(Vx) not(Ey) ... and making it for only real numbers... I'm good in other math like Algebra, Trigonometry and Calculus but this one really burns my mind. Can anyone here give me some tips.

BTW, is this the right forum?

Thanks,
Sarah

 

[daveyinaz]

I'm not sure what it is your asking...just learn the rules of logic I guess...

Not (Vx) is equivalent to (Ex)

and Not (Ey) is equivalent to (Vy)