reserve T for TopSpace,
  A, B for Subset of T;

theorem Th10: :: Corollary to Theorem 2
  A is condensed iff Int Cl A c= A & A c= Cl Int A
proof
  thus A is condensed implies Int Cl A c= A & A c= Cl Int A by Th8,Th9;
  assume that
A1: Int Cl A c= A and
A2: A c= Cl Int A;
A3: A is subcondensed by A2,Th9;
  A is supercondensed by A1,Th8;
  hence thesis by A3;
end;
