Set Theory - Laws
Idempotent:     A+A=A; A*A=A
Commutative     A+B=B+A; A*B=B*A
Associative     A+(B+C)=(A+B)+C
         A*(B*C)=(A*B)*C
Distributive     A*(B+C)=A*B+A*C
Product Identities   {}*A={}; S*A=A
Sum Identities     {}+A=A; S+A=S