# Typing problem of word in  [duplicate]

Possible Duplicate:
What is the “correct” way of embedding text into math mode?

when I use  for mathematics typing, sometimes like $\left\{ x: x is an element of A\right\}$, then it shows "isanelement" by a single word. How do I manage that?

use \text{ is an element of }
• Better yet, \text{$x$ is an element of $A$}, to guarantee consistent amounts of text whitespace between all words in the sentence.