Following up on the previous commit, this slightly generalizes the
lemmas associated to the intuitionistic/spatial/modalelim cases of
iDestruct to support renaming on the fly, and use these to save a
later renaming.

Done with a script by Tej; see
iris/iris!609 for details.

Preserve identifiers in binders where possible, analogous to the support
for destructing existentials in !479.

Fixes #336.

Tej Chajed authored Jul 21, 2020 and Robbert Krebbers committed Jul 21, 2020

When running `iDestruct "H" as (?) "H"`, use the name of the binder in
"H". For example, if "H" has type `∃ y, Φ y`,  we now use `y` as the
name of the variable after freshening. Previously the name was always
the equivalent of running `fresh H`.

The implementation achieves this by forwarding the desired identifier
name through the `IntoExist` typeclass. Identifiers are serialized in
Gallina by using them as the name of a function of type `ident_name :=
unit -> unit`.

Gregory Malecha authored Mar 16, 2020 and Robbert Krebbers committed Mar 16, 2020

- remove "odd" comment
- move atomic triples to bi_scope

Make handling of `AddModal` in `tac_specialize_frame` consistent with that in `tac_specialize_assert`.

The result of `iSpecialize ("H" with "[H1 .. Hn]")` was always put in the
spatial context. This commit strenghtens this tactic by putting the result
in the intuitionistic context if the following conditions hold:

1. The hypothesis `H` is persistent.
2. All the hypotheses `H1 .. Hn` are intuitionistic (or similarly, in case
   `[-H1 .. Hn]` is used, if all remaining hypotheses are intuitionistic).
3. If the pattern `[> ..]` for adding a modality is not used.

Paolo G. Giarrusso authored Nov 22, 2019 and Robbert Krebbers committed Nov 22, 2019

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.

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.

This commit closes issue #265.

This is an alternative to !224.

This is a follow up of !248.