let C be FormalContext; :: thesis: for D being Subset of (ConceptLattice C) holds
( "/\" D,(ConceptLattice C) is FormalConcept of C & "\/" D,(ConceptLattice C) is FormalConcept of C )

let D be Subset of (ConceptLattice C); :: thesis: ( "/\" D,(ConceptLattice C) is FormalConcept of C & "\/" D,(ConceptLattice C) is FormalConcept of C )
ConceptLattice C = LattStr(# (B-carrier C),(B-join C),(B-meet C) #) by CONLAT_1:def 23;
hence ( "/\" D,(ConceptLattice C) is FormalConcept of C & "\/" D,(ConceptLattice C) is FormalConcept of C ) by CONLAT_1:35; :: thesis: verum