Two inequalities displaying side by side, but nicely spaced in LaTeX

Question

In LaTeX, I have two ineqaulites e.g. a \leq b and c \leq d. I want to have a numbered line which has both of these inequalities on it:

a \leq b      c \leq d     (1)

Like this. What's the easiest way to get the spacing to behave itself? Which environment should I use?

Answer 1

The answer is, of course, to use the amsmath package. A perhaps less-known feature of the align environment is to place equations side-by-side, exactly as you are trying to do:

\documentclass{article}
\usepackage{amsmath}
\begin{document}
\begin{align}
a &\leq b   &   c &\leq d     
\end{align}
\end{document}

And if you add multiple lines they'll look good:

\begin{align}
a &\leq b   &   c &\leq d  \\   
a+1 &\leq b+1   &   c+1 &\leq d+1     
\end{align}

Which is the whole reason, really, for not using \quad and other manual spacing commands.