more old Coq failures

theories/fin_map_dom.v

@@ -91,7 +91,10 @@ Proof.
 Qed.
 Lemma dom_insert_lookup {A} (m : M A) i x :
   is_Some (m !! i) → dom D (<[i:=x]>m) ≡ dom D m.
-Proof. intros Hindom%elem_of_dom. rewrite dom_insert. set_solver. Qed.
+Proof.
+  intros Hindom. assert (i ∈ dom D m) by by apply elem_of_dom.
+  rewrite dom_insert. set_solver.
+Qed.
 Lemma dom_insert_subseteq {A} (m : M A) i x : dom D m ⊆ dom D (<[i:=x]>m).
 Proof. rewrite (dom_insert _). set_solver. Qed.
 Lemma dom_insert_subseteq_compat_l {A} (m : M A) i x X :