reserve X for TopStruct,
  A for Subset of X;
reserve X for TopSpace,
  A,B for Subset of X;
reserve X for non empty TopSpace,
  A for Subset of X;
reserve X for TopSpace,
  A,B for Subset of X;
reserve X for non empty TopSpace,
  A, B for Subset of X;

theorem
  [#]X is everywhere_dense
proof
  Int [#]X = [#]X by TOPS_1:15;
  then Cl Int [#]X = [#]X by TOPS_1:2;
  hence thesis;
end;
