
theorem
  for I being 1-element set
  for J being TopSpace-yielding non-Empty ManySortedSet of I
  for i being Element of I
  holds product J, J.i are_homeomorphic
proof
  let I be 1-element set;
  let J be TopSpace-yielding non-Empty ManySortedSet of I;
  let i be Element of I;
  proj(J,i) is being_homeomorphism by Th67;
  hence thesis by T_0TOPSP:def 1;
end;
