GitLab

- It can now also frame under later.
- Better treatment of evars, it now won't end up in loops whenever the goal
  involves sub-formulas ?P and it trying to apply all framing rules eagerly.
- It no longer delta expands while framing.
- Better clean up of True sub-formulas after a successful frame. For example,
  framing "P" in "▷ ▷ P ★ Q" yields just "Q" instead of "▷ True ★ Q" or so.

Par is now defined as an expression of type [∀ X, expr X] (instead of a
value) and we prove that it is stable under weakening and substitution.

It is not a library; it does not contain code, but instead is a core
part of heap_lang.

Thanks to Amin Timany for the suggestion.

Add both non-expansive and contractive functors, and bundle them for the general Iris instance as well as the global functor construction

This allows us to move the \later in the user-defined functor to any place we want.
In particular, we can now have "\later (iProp -> iProp)" in the ghost CMRA.

Tactics like wp_proj should always solve all to_val side-conditions. The
tactic wp_done is used to handle these in a uniform way.