r3tex

commit b59b74f075dad6bd2f81045ee30bf492256a7eef
parent 646d46568af69a88e4a68f8d6fc437907a05b945
Author: robert <robertrussell.72001@gmail.com>
Date:   Sun, 30 Jan 2022 14:28:27 -0800

Make _ active

Diffstat:
M
catcode.tex
 | 
2
+-
M
math.tex
 | 
5
++---
M
mathenc.tex
 | 
2
+-

3 files changed, 4 insertions(+), 5 deletions(-)
diff --git a/catcode.tex b/catcode.tex
@@ -19,7 +19,7 @@
 % \catcode`\^^M=5
 \catcode`\#=6
 \catcode`\^=7
-\catcode`\_=8
+\catcode`\_=13 % Unlike plain, _ is active.
 % \catcode`\^^@=9
 % \catcode`\ =10
 \catcode`\^^I=10
diff --git a/math.tex b/math.tex
@@ -10,6 +10,8 @@
 \def\@mmode{\ifx\next$\ea\@dmmode\else\ea\togmath\fi}
 \def${\futurelet\next\@mmode}
 
+\let_=\Usubscript
+
 \input mathenc
 
 \def\lnot{\neg}
@@ -90,9 +92,6 @@
 \def\,{\relax\ifmmode \mskip\thinmuskip \else \thinspace \fi}
 \def\!{\relax\ifmmode \mskip-\thinmuskip \else \negthinspace \fi}
 
-% _ in math is either subscript or \_
-{\catcode`\_=\active \global\let_=\_}
-
 % Roots
 \newbox\@rootbox
 \def\root#1\of{%
diff --git a/mathenc.tex b/mathenc.tex
@@ -21,7 +21,7 @@
 \mathcode`\[="405B
 \mathcode`\\="026E % \backslash
 \mathcode`\]="505D
-\mathcode`\_="8000 % \_
+\mathcode`\_="8000
 \mathcode`\{="4266
 \mathcode`\|="026A
 \mathcode`\}="5267