TEX_DEFAULT:
A knob to choose teTeX or TeXLive. One can specify in /etc/make.conf.
USE_TEX:
A knob for port developers. Valid keywords are listed in
bsd.tex.mk.
for typesetting verbatim source code listings, including the display
of the source code and its compiled LaTeX or METAPOST output
side-by-side, with automatic width detection and enabled page breaks
(in the source), without the need for specifying the source twice.
WWW: http://www.ctan.org/tex-archive/macros/latex2e/contrib/examplep
PR: ports/167788
Submitted by: Hiroto Kagotani <hiroto.kagotani@gmail.com>