
theorem Th9:
  for L being join-commutative join-associative join-idempotent
  Huntington non empty ComplLLattStr
   holds (Top L)` = Bot L & Top L = (Bot L)`
proof
  let L be join-commutative join-associative join-idempotent Huntington non
  empty ComplLLattStr;
  set a = the Element of L;
  thus (Top L)` = (a + a`)` by Def8
    .= Bot L by Th8;
  hence thesis by Th3;
end;
