theorem :: SETFAM_1:3
  meet SFe c= union SFe
proof
  let i be object;
  assume
A1: i in I;
  then consider Q be Subset-Family of (M.i) such that
A2: Q = SFe.i and
A3: (meet SFe).i = Intersect Q by Def1;
  meet Q c= union Q & Intersect Q = meet Q by A1,A2,SETFAM_1:2,def 9;
  hence thesis by A1,A2,A3,MBOOLEAN:def 2;
end;
