[tex-k] potential errata in The TeXbook and TeX: The Program, Jubilee editions

Doug McKenna doug at mathemaesthetics.com
Wed Nov 1 23:22:58 CET 2023

FWIW, the index entries inside the module

  @<Express consternation over the fact that no alignment is in progress@>

in tex.web include:

  @.Misplaced \&@>
  @.Misplaced \\span@>
  @.Misplaced \\cr@>

which perhaps help elucidate DEK's original motivation for the separate error messages.  If one is looking at the typeset version of the code, one won't notice these index entries.

What I don't understand is why should the following even be considered illegal:


I understand the '&' triggers the error message because of too many left braces, but logically, what is so untoward about opening group contexts one side of the tab mark, and closing them in a balanced way on the other?  Wouldn't that be a feature, not a error?

- Doug McKenna

More information about the tex-k mailing list.