+++ /dev/null
-Open:
-/Coq/Sets/Powerset_facts/Union_commutative.con
-
-We prove the conjunction again:
-
-alias U /Coq/Sets/Ensembles/Ensembles/U.var
-alias V /Coq/Sets/Powerset_facts/Sets_as_an_algebra/U.var
-alias Ensemble /Coq/Sets/Ensembles/Ensemble.con
-alias Union /Coq/Sets/Ensembles/Union.ind#1/1
-alias Included /Coq/Sets/Ensembles/Included.con
-alias and /Coq/Init/Logic/and.ind#1/1
-
-The two parts of the conjunction can be proved in the same way. So we
-can make a Cut:
-
-!C:Ensemble{U:=V}.!D:Ensemble{U:=V}.
- (Included{U:=V} (Union{U:=V} C D) (Union{U:=V} D C))