On Fri, Apr 17, 2015 at 05:07:31PM +0200, Frédéric Wang wrote:
> Hi all,
> Here is a testcase with a dev version of GNUFreeFont:
> As I understand, stretchy U+2F/U+2211/U+27E8/U+27E9 do not have a "glue"
> so we connect them using a rule
AFAIK, The only times TeX (and by extension OpenType math implemenation)
use rules is for radical and fraction bars, everything else is done
using glyph variants and/or repeatable parts. If the font does not
provide the required glyphs no stretching happens.