Ligature request: =? and =?=

[JonasHoefer]

Currently, there is a ligature for ?= but not for the symmetric case =? and not for the combined case =?=. Furthermore, the ligature ?= already looks like it could be incorporated into an arbitrary long arrow/equality, such as ?====, but this is not possible. Because currently ?= exists, =?= looks weird, because only the last two characters are combined.

The analogous ligatures =! and =!= for ! exist, and can be incorporated into arbitrary long arrows/equalities. It would be nice to have a similar behavior for ? in long equals sings. If this is not possible, it would be nice, to have a stylistic set for disabling the ligature ?=, such that =?= looks better.

[tonsky]

Is there a use-case for these?