# predicate logic proof of 2 numbers

For any two different numbers there is an number in between.

I'm trying to write this in predicate logic and have no idea how to do it, since I need 2 variables X and Y? For all x there exists a y such that y - x is positive?

I'm a mong ignore.

• Hint: for any $x$ and $y$, there is a $z$ such that ... – Musa Al-hassy Nov 26 '18 at 11:17