
theorem Th1:
  for L being join-commutative join-associative Huntington non
  empty ComplLLattStr, a, b being Element of L holds (a + b)` = a` *' b`
proof
  let L be join-commutative join-associative Huntington non empty
  ComplLLattStr;
  let a, b be Element of L;
  a + b = (a` *' b`)` by ROBBINS1:17;
  hence thesis by ROBBINS1:3;
end;
