Definition 2.3: let a and b be two sets The Cartesian product of A and B, denoted by AXB, is the set of all ordered pairs(a,b) where a∈ A and b∈B. Hence A×B={(a,b)a∈ A and b∈B Example: Let A=(1, 2, B=x, y, C=a, b, c) A×B={(1,x),(1,y),(2,x)2,y)}; B×A={(x,1),(x,2),y,1),(y,2)}; B×A≠AXB commutative laws XDefinition 2.3: Let A and B be two sets. The Cartesian product of A and B, denoted by A×B, is the set of all ordered pairs ( a,b) where aAand bB. Hence A×B={(a, b)| aAand bB} Example: Let A={1,2}, B={x,y},C={a,b,c}. A×B={(1,x),(1,y),(2,x),(2,y)}; B×A={(x,1),(x,2),(y,1),(y,2)}; B×AA×B commutative laws ×