Square Brackets with Tick
jcb+unicode at inf.ed.ac.uk
Sat Aug 22 11:35:19 CDT 2015
On 2015-08-22, Nigel Small <nigel at nigelsmall.com> wrote:
> 298D; 2990; o # LEFT SQUARE BRACKET WITH TICK IN TOP CORNER
> 298E; 298F; c # RIGHT SQUARE BRACKET WITH TICK IN BOTTOM CORNER
> 298F; 298E; o # LEFT SQUARE BRACKET WITH TICK IN BOTTOM CORNER
> 2990; 298D; c # RIGHT SQUARE BRACKET WITH TICK IN TOP CORNER
> with several code points in between. According to the code point pairs in
> the first and second columns of this file, these particular brackets should
> be paired as the *first and fourth* and the *third and second*. Intuitively
> however, these would actually be *first and second* and *third and fourth*
> if one is to expect consistency.
That's a strange intuition! Mathematical brackets are expected to pair
with left-right symmetry, not rotational symmetry. As in, for example,
floor and ceiling brackets. The pairing in the file is the natural one.
> 1. The current pairing information is correct and the sequence is irregular
> for some historical reason
That will be the explanation. There is no inherent meaning to the
order of codepoints, it's just convenience.
One of the experts here can probably tell us why these four brackets
happen to be coded in this order.
The University of Edinburgh is a charitable body, registered in
Scotland, with registration number SC005336.
More information about the Unicode