[tex-k] inaccuracy on page 215 of The TeXbook

胡亚捷 (Hu Yajie) 2500418497 at qq.com
Tue Oct 13 12:41:54 CEST 2020

Page A215, line 26 says that expansion is suppressed
    Just after a $_3 token that begins math mode, to see if
    another $_3 follows.
However, any character whose category code is 3 would do, not
just $_3. For example, the following program
    \catcode`\?=13 \def?{!}
typesets the equivalent of $ $math$ $ instead of $$math$$.


Previous reports:

(I don't know if I can go through every page before Nov 1...)

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