# Proof using WOP

• March 11th 2013, 08:19 AM
kmerfeld
Proof using WOP
Hello everyone,

I want to prove that for postive integers $x, y, x+y \ne y$. I want to do this using the WOP. Here's what I have done so far:

Suppose for some postive integer $x, \exists y$ such that $y=x+y$. By the WOP, there exists a smallest $x_0$ such that $y=x_0+y$. Now I think I may have to apply the WOP again, but am not sure. Any advice?

Thanks a lot,

Kevin
• March 11th 2013, 08:28 AM
Plato
Re: Proof using WOP
Quote:

Originally Posted by kmerfeld
P.S. Is there a way to enter LaTex code?

[TEX]x+y\ne y [/TEX] gives $x+y\ne y$
If you click on the “go advanced tab” you should see $\boxed{\Sigma}$ on the tool-bar. That gives the [TEX]..[/TEX] wrap. Your LaTeX code goes between them.
• March 11th 2013, 08:37 AM
kmerfeld
Re: Proof using WOP
$x+y\ne y$ Got it. Thanks