    ‘Sentenge 1: Under, Béalean ‘algebra’, W has thé‘a set-that ig  Closed Under.thé two: commutative..binary’ operations. and  ‘that “tan ‘be described” by’ any: of various systenié ‘of  " postulate’s all of which.can be. deduced from:the-postulates  that an‘identity elément exists foreach Operation; that each  ‘operation is distributive ovér the: other, and/that for every .  element in ‘the’ Set there is another-elemerit which: when  combined with the frst’ under-one ‘of. the operations yields  the “identity’ ‘element. ofthe “other.” opérationicunder the  _ bperationis of taking intersections and tinions, the subséis'of  a:given set forma Boplean algebra ~, OS  ‘Sentence 2: Boolean algebra is a bigher tier of matherhatlos  than.caleulus.. 7 “2° ts + oh                   