Glyphs ∨, ∧ are swapped in Ubuntu Mono

[Florian Lorenzen]

In Ubuntu Mono the glyphs ∨ (0x2227), ∧ (0x2228) seem to be swapped. This is very puzzling if you, e.g., input a logical `or' instead of an `and' in your theorem prover.

The problem appears in Ubuntu 11.10 with the package ttf-ubuntu-font-family of version 0.80-0ubuntu1~medium.

[adoa (adoa)]

Hello Florian,

on my computer, the glyphs are definitely not swapped.

According to http://www.utf8-chartable.de/unicode-utf8-table.pl?start=8704

0x2227 should be the ‘logical and’
0x2228 should be the ‘logical or’

Just as they are displayed on my system.
You seem to have it swapped.

Are you sure that this is a problem of the font?
Can you reproduce inconsistencies with LibreOffice Writer, for example?
Do different fonts display the same text with different glyphs?
What happens if you enter
‘ctrl+shift+u’ release all keys, then ‘2227’
in LibreOffice Writer?
That should produce the utf-8 symbol 0x2227, as described here: https://en.wikipedia.org/wiki/Unicode_input#In_Linux

[adoa (adoa)]

By the way, I use Ubuntu 11.10 with ttf-ubuntu-font-family version 0.80-0ubuntu1~medium, as well.

[Paul Sladen (sladen)]

Florian: to mirror adoa's comments; U+2227 (∧) points upwards, and U+2228 (∨) points downwards. In your example at the start of the bug report, they are (incorrectly) swapped. The error is probably occuring at some time earlier. How did you enter them? Did you use the "Ctrl-Shift-u 2 2 2 7 enter" method, or from eg. copying and pasting from another piece of software.

(Ubuntu Mono does not—yet—including logical AND and OR codepoints as of v0.80, so it's probably invalid for the Ubuntu Font Family, but I'm still interested in where the error might be coming from).

[Florian Lorenzen (florian-lorenzen)]

I'm sorry, I swapped the two code points in my report.

I experienced the problem in GNU Emacs, both using the TeX and the ucs input method. Find attached two screenshots of the same buffer, one using the Ubuntu Mono font, the other one using DejaVu Sans Mono. The symbols are flipped.

I do not experience the problem in the GNOME Terminal or LibreOffice Writer when directly entering the code using the C-S u method.

Since Paul mentions that Ubuntu Mono does not include logical and/or glyphs, I'm surprised where they come from and why Emacs gets them wrong and GNOME Terminal or LibreOffice Writer do not.

But this looks like an Emacs problem. Sorry for blaming the font at first place.

[Paul Sladen (sladen)]

I can't reproduce this. I'm using the following:

  $ emacs -fn 'Ubuntu Mono 20'
  C-x 8 enter 2227 enter
  C-x 8 enter 2228 enter

  $ emacs -fn 'DejaVu Sans Mono 20'
  C-x 8 enter 2227 enter
  C-x 8 enter 2228 enter

Florian, could you possibly post the exact sequence of instructions that you're using when you're seeing this?

[Florian Lorenzen (florian-lorenzen)]

Paul, I just reproduced your input and with Ubuntu Mono the glyphs are flipped, with DejaVu, they are not.

I also called emacs with `-q' to exclude local (mis-)configurations on my side but this doesn't affect the phenomenon.

Usually, I use the TeX input method but it also does not work with C-x 8 RET nnnn RET.

Thanks for your help, btw.

Florian

[Launchpad Janitor (janitor)]

[Expired for Ubuntu Font Family because there has been no activity for 60 days.]

[Paul Sladen (sladen)]

Please can you run 'gucharmap'. Select "Ubuntu Mono"; Search for U+2227, then right-click and see what font it is actually using for those characters on your specific machine.

Prompted by seeing a similar inversion report for FreeSerif:

  http://lists.alioth.debian.org/pipermail/pkg-fonts-devel/2012-February/009593.html
  http://bugs.debian.org/659527

over U+2293 and U+2294.

[Florian Lorenzen (florian-lorenzen)]

gucharmap says it uses DejaVu Sans for U+2227 and U+2228.

Regards,

Florian