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

[Gavin Smith]

On Mon, Jul 03, 2017 at 05:31:14PM +0200, Benno Schulenberg wrote:
> 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.

Interesting observation.

When I tried with these characters, I got an error:
./test.texi:3: Undefined control sequence.
<argument> @Box 
                
@ensuredmath #1->address@hidden #1
                           $
@U ...d, address@hidden @else @csname uni:address@hidden 
                                                  @fi 
l.3 @U{25A1}
            
? 

@Diamond is not defined either, nor is @Join.

I think these definitions are wrong.

There are several more definitions that are wrong:

@U{2201} = @complement
@U{21DD} = @leadsto
@U{2127} = @mho
@U{21BE} = @upharpoonright
@U{228F} = @sqsubset
@U{2290} = @sqsupset
@U{22B4} = @unlhd
@U{22B5} = @unrhd

They should probably all be removed.

There are @diamond and @diamondsuit but I haven't checked if they would be
suitable to use for the Unicode character in question.