
theorem Th11: :: 1.3. THEOREM, p. 179
  for S,T being complete LATTICE for d being sups-preserving Function of S,T
  holds LowerAdj UpperAdj d = d
proof
  let S,T be complete LATTICE;
  let d be sups-preserving Function of S,T;
  [UpperAdj d, d] is Galois by Def2;
  hence thesis by Def1;
end;
