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

Fixes #336.

Tej Chajed authored 4 years ago and Robbert Krebbers committed 4 years ago

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 4 years ago and Robbert Krebbers committed 4 years ago

- it doesn't seem to conflict with anything in Ltac

Here's one case this lemma might be useful. Suppose we want to
programmatically generate namespaces for e.g. locks:

```
Definition lockN (l : loc) := nroot .@ "lock" .@ l.
```

Then to know that two such namespaces are disjoint, we need to know
that the corresponding locations are distinct. For that we use
the lemma here introduced.

```
Lemma ne l1 l2 v1 v2 :
  l1 ↦ v1 -∗ l2 ↦ v2 -∗ ⌜l1 ≠ l2⌝.
Proof. iApply mapsto_mapsto_ne. (* goal ¬ ✓ 2%Qp *) by intros []. Qed.
```

Simon Friis Vindum authored 4 years ago and Ralf Jung committed 4 years ago

Removes auth_both_op and renames auth_both_frac_op into auth_both_op.

- all ascii notation is marked "only parsing" so this PR shouldn't
  change anything for anyone using only unicode notation.
- the algorithm for creating an ascii notation is pretty simple.
  - \ast -> *
  - \triangleright -> |>
  - \vee -> \/
  - \wedge -> /\
  - \forall -> forall
  - \exists -> exists
  - \ast -> **