[proof] Move proofs that have an associated constant to `Lemmas`

The main idea of this PR is to distinguish the types of "proof object"
`Proof_global.t` and the type of "proof object associated to a
constant, the new `Lemmas.t`.

This way, we can move the terminator setup to the higher layer in
`vernac`, which is the one that really knows about constants, paving
the way for further simplification and in particular for a unified
handling of constant saving by removal of the control inversion here.

Terminators are now internal to `Lemmas`, as it is the only part of
the code applying them.

As a consequence, proof nesting is now handled by `Lemmas`, and
`Proof_global.t` is just a single `Proof.t` plus some environmental
meta-data.

We are also enable considerable simplification in a future PR, as this
patch makes `Proof.t` and `Proof_global.t` essentially the same, so we
should expect to handle them under a unified interface.

1 files changed, 4 insertions, 5 deletions

diff --git a/stm/proofBlockDelimiter.ml b/stm/proofBlockDelimiter.ml
index dfa681395a..7ff6ed9dfb 100644
--- a/stm/proofBlockDelimiter.ml
+++ b/stm/proofBlockDelimiter.ml
@@ -48,15 +48,14 @@ let simple_goal sigma g gs =
 let is_focused_goal_simple ~doc id =
   match state_of_id ~doc id with
   | `Expired | `Error _ | `Valid None -> `Not
-  | `Valid (Some { Vernacstate.proof }) ->
-    Option.cata (fun proof ->
-        let proof = Proof_global.get_current_pstate proof in
-        let proof = Proof_global.give_me_the_proof proof in
+  | `Valid (Some { Vernacstate.lemmas }) ->
+    Option.cata (Lemmas.Stack.with_top_pstate ~f:(fun proof ->
+        let proof = Proof_global.get_proof proof in
         let Proof.{ goals=focused; stack=r1; shelf=r2; given_up=r3; sigma } = Proof.data proof in
         let rest = List.(flatten (map (fun (x,y) -> x @ y) r1)) @ r2 @ r3 in
         if List.for_all (fun x -> simple_goal sigma x rest) focused
         then `Simple focused
-        else `Not) `Not proof
+        else `Not)) `Not lemmas
 
 type 'a until = [ `Stop | `Found of static_block_declaration | `Cont of 'a ]