L2/18-049R

Title: Pair mappings missing from BidiMirroring.txt
Author: Roozbeh Pournader
Date: 2018-01-24

UTC Action Item 153-A82 asked the author and Murray Sargent to check
BidiMirroring.txt for other possible pair mappings. After some investigation,
the author found the following pairs which are missing from Unicode 10.0 version
of BidiMirroring.txt. They should be added to Unicode 11.0 as pairs.

(Note that some of these had already been reported by others earlier and have
been accepted by UTC to be added to Unicode 11.0. This document tries to collect
all additions in relation to Unicode 10.0.)

Perfect pairs
=============

The following pairs are perfect pairs, in the sense that the bidi-mirrored
version of each should appear exactly like the other in a good font:

U+2220 ∠ U+29A3 ⦣
U+2221 ∡ U+299B ⦛
U+2222 ∢ U+29A0 ⦠
U+2224 ∤ U+2AEE ⫮
U+2245 ≅ U+224C ≌
U+22B8 ⊸ U+27DC ⟜
U+29A4 ⦤ U+29A5 ⦥
U+29A8 ⦨ U+29A9 ⦩
U+29AA ⦪ U+29AB ⦫
U+29AC ⦬ U+29AD ⦭
U+29AE ⦮ U+29AF ⦯
U+29E8 ⧨ U+29E9 ⧩

Best fit pairs
==============

The following characters are "[BEST FIT]" pairs. They are similar to existing
pairs in BidiMirroring.txt that may need to change the direction of the
negation slash (U+2268 ≨ and U+2269 ≩) or the direction of tilde(s) (U+2272 ≲
and U+2273 ≳), but are otherwise bidi mirroring pairs.

Negation best fits
------------------
U+2A87 ⪇ U+2A88 ⪈
U+2AB1 ⪱ U+2AB2 ⪲
U+2AB5 ⪵ U+2AB6 ⪶
U+2ACB ⫋ U+2ACC ⫌

Tilde best fits
---------------
U+2A85 ⪅ U+2A86 ⪆
U+2A8D ⪍ U+2A8E ⪎
U+2A8F ⪏ U+2A90 ⪐
U+2A9D ⪝ U+2A9E ⪞
U+2A9F ⪟ U+2AA0 ⪠
U+2AB7 ⪷ U+2AB8 ⪸
U+2AC7 ⫇ U+2AC8 ⫈
U+2AC9 ⫉ U+2ACA ⫊

Tilde and negation best fits
----------------------------
U+2A89 ⪉ U+2A8A ⪊
U+2AB9 ⪹ U+2ABA ⪺

Other best fits
---------------
U+2A7B ⩻ U+2A7C ⩼