fix printing notation when importing heap_lang.lang after heap_lang.notation

tests/heap_lang.v

-(** This file is essentially a bunch of testcases. *)
 From iris.program_logic Require Export weakestpre total_weakestpre.
-From iris.heap_lang Require Export lang.
-From iris.heap_lang Require Import adequacy.
-From iris.heap_lang Require Import proofmode notation.
+From iris.heap_lang Require Import lang adequacy proofmode notation.
+(* Import lang *again*. This used to break notation. *)
+From iris.heap_lang Require Import lang.
 Set Default Proof Using "Type".
 
 Section tests.

theories/heap_lang/lang.v

@@ -529,13 +529,3 @@ Canonical Structure heap_lang := LanguageOfEctx heap_ectx_lang.
 
 (* Prefer heap_lang names over ectx_language names. *)
 Export heap_lang.
-
-(** Define some derived forms *)
-Notation Lam x e := (Rec BAnon x e).
-Notation Let x e1 e2 := (App (Lam x e2) e1).
-Notation Seq e1 e2 := (Let BAnon e1 e2).
-Notation LamV x e := (RecV BAnon x e).
-Notation LetCtx x e2 := (AppRCtx (LamV x e2)).
-Notation SeqCtx e2 := (LetCtx BAnon e2).
-Notation Skip := (Seq (Lit LitUnit) (Lit LitUnit)).
-Notation Match e0 x1 e1 x2 e2 := (Case e0 (Lam x1 e1) (Lam x2 e2)).

theories/heap_lang/notation.v

@@ -2,6 +2,17 @@ From iris.program_logic Require Import language.
 From iris.heap_lang Require Export lang tactics.
 Set Default Proof Using "Type".
 
+(** Define some derived forms. Happens in the same file because the order of
+    this and the following notations being defined is very relevant. *)
+Notation Lam x e := (Rec BAnon x e).
+Notation Let x e1 e2 := (App (Lam x e2) e1).
+Notation Seq e1 e2 := (Let BAnon e1 e2).
+Notation LamV x e := (RecV BAnon x e).
+Notation LetCtx x e2 := (AppRCtx (LamV x e2)).
+Notation SeqCtx e2 := (LetCtx BAnon e2).
+Notation Skip := (Seq (Lit LitUnit) (Lit LitUnit)).
+Notation Match e0 x1 e1 x2 e2 := (Case e0 (Lam x1 e1) (Lam x2 e2)).
+
 Coercion LitInt : Z >-> base_lit.
 Coercion LitBool : bool >-> base_lit.
 Coercion LitLoc : loc >-> base_lit.

theories/heap_lang/proofmode.v

@@ -2,6 +2,7 @@ From iris.program_logic Require Export weakestpre total_weakestpre.
 From iris.proofmode Require Import coq_tactics.
 From iris.proofmode Require Export tactics.
 From iris.heap_lang Require Export tactics lifting.
+From iris.heap_lang Require Import notation.
 Set Default Proof Using "Type".
 Import uPred.