On three laws typical of Booleanity

This paper's goal is to prove that the only de Morgan algebras and the only ortholattices in which the three laws a'+b = a'+a.b,a.(a'+b)/spl les/b, and (a.b')'= b + a'b' do hold, are Boolean algebras. That is, in those two usual generalizations of Boolean algebras these laws characterize Booleanity.