diff options
| author |  herbelin <herbelin@85f007b7-540e-0410-9357-904b9bb8a0f7> | 2007-10-03 14:41:25 +0000 |
|---|---|---|
| committer | herbelin <herbelin@85f007b7-540e-0410-9357-904b9bb8a0f7> | 2007-10-03 14:41:25 +0000 |
| commit | 95483a55c228a0c3d9628a8b4e6cc45c84b8c894 (patch) | |
| tree | 392b1080d0c4f22020db6566c12210551f120701 /theories/Init | |
| parent | 1bead2a1ef23f2a281613093d7861815279e336d (diff) | |
Révision de theories/Logic concernant les axiomes de descriptions.
Mise à jour du tableau des axiomes dans la FAQ.
git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@10170 85f007b7-540e-0410-9357-904b9bb8a0f7
Diffstat (limited to 'theories/Init')
| -rw-r--r-- | theories/Init/Logic.v | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/theories/Init/Logic.v b/theories/Init/Logic.v index 8deb362cd..f38a651d0 100644 --- a/theories/Init/Logic.v +++ b/theories/Init/Logic.v @@ -314,8 +314,22 @@ Proof. auto. Qed. -(** Being inhabited *) +(** * Being inhabited *) + +(** The predicate [inhabited] can be used in different contexts. If [A] is + thought as a type, [inhabited A] states that [A] is inhabited. If [A] is + thought as a computationally relevant proposition, then + [inhabited A] weakens [A] so as to hide its computational meaning. + The so-weakened proof remains computationally relevant but only in + a propositional context. +*) Inductive inhabited (A:Type) : Prop := inhabits : A -> inhabited A. Hint Resolve inhabits: core. + +Lemma exists_inhabited : forall (A:Type) (P:A->Prop), + (exists x, P x) -> inhabited A. +Proof. + destruct 1; auto. +Qed. |