@U{xxxx} -- some TeX characters with a capital don't seem to work

[Benno Schulenberg]

Hi,

I'm trying to get a special character into the nano manual,
so I specify it with @U{25C7}.  That works fine for the Info
and HTML output, but when I try to make a PDF, I get:

../../../.././nano.texi:426: Undefined control sequence.
<argument> @Diamond

@ensuredmath #1->address@hidden #1
                           $
@U ...d, address@hidden @else @csname uni:address@hidden
                                                  @fi
l.426 enter the symbol "@U{25C7}
                                ", a diamond.


If I change 25C7 to 25A1 or to 2A1D, I get the same failure.
When I try some of the surrounding values, it works fine.
Notice what those three values have in common:

  \DeclareUnicodeCharacter{25A1}{\ensuremath\Box}%
  \DeclareUnicodeCharacter{25C7}{\ensuremath\Diamond}%
  \DeclareUnicodeCharacter{2A1D}{\ensuremath\Join}%

The name of each of them starts with an uppercase letter.
But that can't be the criterion, because 21D1 or 211C work
fine, for example.

What could be going on?  Am I missing some TeX file?

(I have the most recent texinfo.tex (from June 18) installed.)

Attached is the log file of running texi2any --pdf doc/nano.texi.

Benno

nano.log
Description: Text Data