diff options
Diffstat (limited to 'src/common/Optionmonad.v')
| -rw-r--r-- | src/common/Optionmonad.v | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/src/common/Optionmonad.v b/src/common/Optionmonad.v index 14a41ef..4a80ff8 100644 --- a/src/common/Optionmonad.v +++ b/src/common/Optionmonad.v @@ -63,4 +63,14 @@ Module Option <: Monad. End Option. -Module OptionExtra := MonadExtra(Option). +Module OptionExtra. + Module OE := MonadExtra(Option). + Export OE. + + Lemma mfold_left_Some : + forall A B f x n y, + @mfold_left A B f x n = Some y -> + exists n', n = Some n'. + Proof. induction x; intros; destruct n; eauto. Qed. + +End OptionExtra. |