“…The Boolean theory is much simpler than free probability theory, and at this point lacks its depth, primarily because of the lack of the random matrix techniques. Nevertheless, it has a number of crucial properties since it comes from a universal product; in fact, by a theorem of Speicher [Spe97] (see also [BGS02,Mur03]), Boolean, free, and classical theories are exactly the only ones which arise from universal products (respectively, Boolean, free, and tensor) which do not depend on the order of the components. A sample of work on Boolean probability theory includes [SW97,Pri01,Ora02,Fra03,KY04,Mło04,Len05,Sto05,Ber06].…”