# [texhax] Equation problem

Barbara Beeton bnb at ams.org
Tue Jan 10 17:55:28 CET 2006

peter flom writes,

This one has me stumped......

When I typeset

\documentclass{article}
\usepackage{amsmath, amssymb, latexsym, amsthm}
\begin{document}
$$r_{q,i}=\phi^{-1}\left{F(y_i;\hat{\mu},\hat{\phi})\right}$$
\end{document}

I get an error that there is a missing { right after the first \phi,
but I see the delimiter right there.
But if I typeset just the equation, using WinEdt shift ctrl c, the
equation looks fine.

i really don't know how winedt gets this to work,
because the syntax isn't correct.

you can only use \left and \right with real fences.
since the ordinary braces are significant to tex
as grouping characters, you need to code them as
\{ and \} if you're using them for fences.  so if
$$r_{q,i}=\phi^{-1}\left\{F(y_i;\hat{\mu},\hat{\phi})\right\}$$