Matthieu Sozeau authored 5 years ago and Robbert Krebbers committed 5 years ago

That should not be allowed

Also refactor the proofs to make better reuse of existing lemmas.

Paolo G. Giarrusso authored 5 years ago and Robbert Krebbers committed 5 years ago

When proving `foo` through a fixpoint, Coq's guardedness checker needs to see to
which arguments `foo` is applied. Opaque lemmas applied to `foo` itself prevent
that, so make them transparent.
* Make `IntoEmpValid` lemmas transparent.
* Expose application of `IntoEmpValid` instance to its argument.
* Add comment to `tac_pose_proof`

This MR brings back the type of `tac_pose_proof` to the one it had before !329.
Hence, this seems worth a comment.

This fixes the problem in iris/iris!275 (comment 42062)

This fixes some issues in GPS and RustBelt-relaxed, where the old
unification algorithm is now too weak.

This is needed to fix RustBelt-related. Since type classes are no longer
over-eagerly resolved, the `biIndex` now sometimes contains an evar.

Also, rewrite `iIntoEmpValid`. Now, instead of using Ltac to traverse
the type of the term and generate goals for the premises, we repeatedly
apply a series of lemmas. This has the advantage that it works up to
convertability, and we no longer need the `eval ...` hacks.

To prepare for https://github.com/coq/coq/pull/10762

The space should not be there and was added in oversight. This also provides
forwards compatibility with https://github.com/coq/coq/pull/10832.