
theorem
  for L being complete LATTICE holds DsupClOpers L, (Subalgebras L) opp
  are_isomorphic
proof
  let L be complete LATTICE;
  set f = (ClImageMap L)|DsupClOpers L;
  reconsider g=corestr f as Function of DsupClOpers L, (Subalgebras L) opp by
Th28;
  take g;
  Image f = (Subalgebras L) opp by Th28;
  hence thesis;
end;
