GitLab

rel_apply_ tactic pose the lemma before searching for a place to apply
it.
This is in accordance with <https://gitlab.mpi-sws.org/FP/iris-coq/commit/211dc7cad10da872d2840f73acd85eed0b82f7b4>

- Define several versios of bind and return for the relational
  interpretation
- Use those operations to prove some compatibility lemmas
  without unfolding the definitions
- Get rid of the definition unfolding in a part of the stack
  refinement proof

+ add some discussion in comments.org

Γ ⊧ e1 ≤ e2 : τ now means
∀ Δ, {⊤,⊤;Δ;Γ} ⊧ e1 ≤ e2 : τ

- The typeclass `PureExec e1 e2` controls pure deterministic
  reductions
- General tactics rel_pure_l and rel_pure_r that depend on that typeclass
- The same typeclass can be used for WP tactics and tp tactics, potentially

- Use the type of literals in `val`
- Notation for `match`
- "Better" coercions