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Diffstat (limited to 'theories/Logic/ConstructiveEpsilon.v')
| -rw-r--r-- | theories/Logic/ConstructiveEpsilon.v | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/theories/Logic/ConstructiveEpsilon.v b/theories/Logic/ConstructiveEpsilon.v index 3753b97b..ff70c9fb 100644 --- a/theories/Logic/ConstructiveEpsilon.v +++ b/theories/Logic/ConstructiveEpsilon.v @@ -6,7 +6,7 @@ (* * GNU Lesser General Public License Version 2.1 *) (************************************************************************) -(*i $Id: ConstructiveEpsilon.v 11238 2008-07-19 09:34:03Z herbelin $ i*) +(*i $Id: ConstructiveEpsilon.v 12112 2009-04-28 15:47:34Z herbelin $ i*) (** This module proves the constructive description schema, which infers the sigma-existence (i.e., [Set]-existence) of a witness to a @@ -14,8 +14,8 @@ predicate from the regular existence (i.e., [Prop]-existence). One requires that the underlying set is countable and that the predicate is decidable. *) -(** Coq does not allow case analysis on sort [Set] when the goal is in -[Prop]. Therefore, one cannot eliminate [exists n, P n] in order to +(** Coq does not allow case analysis on sort [Prop] when the goal is in +[Set]. Therefore, one cannot eliminate [exists n, P n] in order to show [{n : nat | P n}]. However, one can perform a recursion on an inductive predicate in sort [Prop] so that the returning type of the recursion is in [Set]. This trick is described in Coq'Art book, Sect. |