Math & Science ⇒ Difference between \[ \] and $ $

[mdrapk]

I fear I'm about to lose my head for this: what is the difference between the two constructs above?

I use $ A = \bigcup_{j=1}^n$ and I get the limits on the side of the U symbol. If I use \[ A = \bigcup{j=1}^n \] I get limits above and below (as I wanted).

Is \[ \] invoking some other environment? I'm not even a novice - that would take another ten years.

[localghost]

The TeX syntax $ … $ is for in-line math mode. It's LaTeX equivalent is \( … \). In in-line math mode limits to operators (integrals, sums, …) are typeset beside them in order not to disturb the line spacing. You can force limits above and below the operators by either using \limits directly after an operator command or \displaystyle at the beginning of a math expression.

On the other hand \[ … \] starts a displayed math environment (for unnumbered equations) where limits are typeset below and above operators by default. To typeset limits beside operators here you can use \nolimits as counterpart to the above mentioned \limits.


Further reading:

• The »Math mode« document

Thorsten

[mdrapk]

Thank you. That was very clear and helpful. I also appreciate the additional reference. I have much to learn.
Tony