reserve T for TopSpace;
reserve T for non empty TopSpace;
reserve F for Subset-Family of T;

theorem Th51:
  Int Cl(meet F) c= meet(Int Cl F)
proof
A1: Int(meet Cl F) c= meet(Int Cl F) by Th28;
  Int Cl(meet F) c= Int meet(Cl F) by Th14,TOPS_1:19;
  hence thesis by A1;
end;
