2 /Coq/Sets/Powerset_facts/Sets_as_an_algebra/Union_commutative.con
4 We prove the conjunction again:
6 alias Ensemble /Coq/Sets/Ensembles/Ensembles/Ensemble.con
7 alias Union /Coq/Sets/Ensembles/Ensembles/Union.ind#1/1
8 alias Included /Coq/Sets/Ensembles/Ensembles/Included.con
9 alias and /Coq/Init/Logic/Conjunction/and.ind#1/1
11 The two parts of the conjunction can be proved in the same way. So we
14 !V:Set.!C:(Ensemble V).!D:(Ensemble V).(Included V (Union V C D)