RE: Difference between EM QUAD and EM SPACE

From: Edward Cherlin (
Date: Wed Jul 12 2000 - 02:14:52 EDT

At 2:09 AM -0800 7/11/00, Roozbeh Pournader wrote:
>On Mon, 10 Jul 2000, Jonathan Coxhead wrote:
> > In TeX, the difference is that an EM QUAD (\qquad) and an EN QUAD
> > (\quad) provide spaces that are legitimate breakpoints for lines within a
> > paragraph; while EM SPACE, EN SPACE (\enspace) and THIN SPACE (\thinspace)
> > produce horizontal space that cannot cause a line-break.

Very close, except for the size of the quads.

>I don't think so. I remember thatn in TeX, \quad was an an em quad, and
>\qquad a double em quad. Would someone look at a good source for that?


Knuth says

The macros \enskip, \quad, and \qquad provide spaces that are
legitimate breakpoints within a paragraph; \enspace, \thinspace, and
\negthinspace produce space that cannot cause a break...

\def\quad{\hskip1em\relax} \def\qquad{\hskip2em\relax}
\def\enspace{\kern.5em }
\def\thinspace{\kern .16667em }...

The TeXBook, p. 352.

Roughly, then

\enskip ~ en space
\quad ~ em space
\qquad ~ 2em space
\enspace ~ en kern
\thinspace ~ thin kern

Not the most enlightening choice of names, but we have that problem as well.

Edward Cherlin
"A knot!" exclaimed Alice. "Oh, do let me help to undo it."
Alice in Wonderland

This archive was generated by hypermail 2.1.2 : Tue Jul 10 2001 - 17:21:05 EDT