Proposal: Deprecate ExistentialQuantification

[Niklas Broberg]

> Discussion period: 2 weeks

Returning to this discussion, I'm surprised that so few people have
actually commented yea or nay. Seems to me though that...
* Some people are clearly in favor of a move in this direction, as
seen both by their replies here and discussion over other channels.
* Others are wary of deprecating anything of this magnitude for
practical reasons.
* No one has commented in true support of the classic existential
syntax, only wanting to keep it for "legacy" reasons.

I'm in no particular hurry to see this deprecation implemented, and I
certainly understand the practical concerns, but I would still very
much like us to make a statement that this is the direction we intend
to go in the longer run. I'm not sure what the best procedure for
doing so would be, but some sort of soft deprecation seems reasonable
to me.

Further thoughts?

Cheers,

/Niklas