1 files changed, 21 insertions, 0 deletions
diff --git a/lib/OptionMonad.v b/lib/OptionMonad.v
index 824a9c2f..18430e04 100644
--- a/lib/OptionMonad.v
+++ b/lib/OptionMonad.v
@@ -13,6 +13,27 @@ Local Open Scope option_monad_scope.
 
 (** Simple tactics for option-monad *)
 
+Ltac deepest_match exp := 
+  match exp with
+  | context f [match ?expr with | _ => _ end] => ltac: (deepest_match expr)
+  | _ => exp
+  end.
+
+Ltac autodestruct :=
+  let EQ := fresh "EQ" in 
+  match goal with
+  | |- context f [match ?expr with | _ => _ end] => 
+    let t := ltac: (deepest_match expr) in
+    destruct t eqn:EQ; generalize EQ; clear EQ; congruence || trivial
+  end.
+
+(* deprecated version of "autodestruct". the new one seems a better replacement *)
+Ltac dummy_autodestruct := 
+  let EQ := fresh "EQ" in 
+  match goal with
+  | |- context f [match ?expr with | _ => _ end] => destruct expr eqn:EQ; generalize EQ; clear EQ; congruence || trivial
+  end.
+
 Lemma destruct_SOME A B (P: option B -> Prop) (e: option A) (f: A -> option B):
   (forall x, e = Some x -> P (f x)) -> (e = None -> P None) -> (P (SOME x <- e IN f x)).
 Proof.