[tex-k] Possible error in The TeXbook Chapter 24

Kim Young Min y at example.kr
Tue Oct 22 07:45:46 CEST 2019


The TeXbook p. 270 states the formal syntax of <unit of measure> as:

> <unit of measure>\is<optional spaces><internal unit>
>   \alt<optional {\tt true}><physical unit>


> <optional {\tt true}>\is[true]\alt<empty>

However, trying it out shows <optional spaces> is allowed around <optional
true>, i.e., `\kern3.5\space\space true\space\space pt` works.

This is consistent with TeX: The Program section 453, which uses
scan_keyword for scanning true.

So the formal syntax for <optional true> should be:

> <optional {\tt true}>\is<optional spaces>
>   \alt<optional {\tt true}>[true]<optional spaces>

Best regards,
Kim Young Min

Kim Young Min
BSc student

-------------- next part --------------
An HTML attachment was scrubbed...

More information about the tex-k mailing list