| − | The '''cartesian product''' of 2 sets ''A'' and ''B'' is the set (usually denoted by ''A × B'') consists of all ordered pairs ''(a, b)'' where <math>a \in A</math> and <math>b \in B</math>. The Cartesian product is named after [[René Descartes]] who invented this concept. | + | The '''Cartesian product''' of 2 sets ''A'' and ''B'' is the set (usually denoted by ''A × B'') consists of all ordered pairs ''(a, b)'' where <math>a \in A</math> and <math>b \in B</math>. The Cartesian product is named after [[René Descartes]] who invented this concept. |