[comp.text.tex] restricting functions

ruberman@BINAH.CC.BRANDEIS.EDU (03/07/91)

I wonder if anyone has a TeX or LaTeX macro that will display (nicely) the
restriction of functions in a mathematical paper.  That is, the name of the
function (say `f') followed by a vertical line extending below the current line
with some subspace. I can do this in many ways, but none of them seem to look
right.  For example: $f_{|X}$  doesn't look right since the vertical line
doesn't extend high enough, and the X is lowered too much. The best I can come
up with is variations on the theme of: $f\lower.5ex\hbox{$|X$}$, which still
doesn't quite make it.  In the paper in question, this construction occurs
in places in subscripts, so a \mathchoice construction is presumably needed.

If anyone has a way of doing this which is in reasonable accordance with 
standard principles of mathematical typography, please let me know.
	Daniel Ruberman
	ruberman@binah.cc.brandeis.edu
	ruberman@brandeis.bitnet	

krab@iesd.auc.dk (Kresten Krab Thorup) (03/08/91)

Hi Daniel

What you ask for, is already there; try

	$\left.f\right|_x=\int_{\mathrm{A}}x^2\;dx$
	        ^^^^^^^^^

/Kresten Krab Thorup
--


			        /  |__  __/   |  /
			       /_/_|   / ___/   |
			    _____/  __/ __/__/__|
				     ____/

			LaTeX's not crap --- that's me