As suggested by @jjourdan, and proved in the ordered RA model by @amintimany.

This should solve the paradox in #149.

General Invariant Tactic

See merge request FP/iris-coq!116

Fix regression in iGPS caused by eebe055b.

See merge request FP/iris-coq!120

As reported by @jjourdan: framing now no longer back tracks on whether
to strip laters or not. When framing below a later, we now only make it
strip laters of the head of the frame.

weaken BI axiom persistently_and_sep_elim and re-derive the stronger form

See merge request FP/iris-coq!119

For better support for eliminating affine/absorbing separating
conjunctions in the persistent context/under a plainness/persistence
modality.

This regression was caused by a bug in handling spec patterns.