reserve X for non empty TopSpace;
reserve Y for non empty TopStruct;
reserve x for Point of Y;
reserve Y for non empty TopStruct;
reserve X for non empty TopSpace;
reserve x,y for Point of X;
reserve A, B for Subset of X;
reserve P, Q for Subset of X;
reserve Y for non empty TopStruct;
reserve X for non empty TopSpace,
  Y0 for non empty SubSpace of X;

theorem
  for A being non empty Subset of Y holds A is Subset of Sspace(A)
proof
  let A be non empty Subset of Y;
  the carrier of Sspace(A) c= the carrier of Sspace(A);
  hence thesis by Lm3;
end;
