===== Cartesian product ===== ==== Set ==== | @#55CCEE: context | @#55CCEE: $X,Y$ ... small set | | @#FFBB00: definiendum | @#FFBB00: $ p\in X \times Y $ | | @#DDDDDD: range | @#DDDDDD: $ x\in X$ | | @#DDDDDD: range | @#DDDDDD: $ y\in Y$ | | @#55EE55: postulate | @#55EE55: $ \exists x,y.\,p=\langle x,y\rangle $ | ==== Discussion ==== ^ $ X \times Y\subset \mathcal{P}(\mathcal{P}(X \cap Y))$ ^ === Definitions === In accordance to the defintion of the n-tuple in [[Ordered pair]], we set ^ $ X_1\times X_2\times X_3 \equiv (X_1\times X_2)\times X_3 $ ^ and inductively for ^ $ X_1\times X_1\times X_3\times \ \dots\ \times X_{n-1}\times X_n \equiv ((\dots((X_1\times X_2)\times X_3)\times\ \dots\ )\times X_{n-1})\times X_n $ ^ ==== Parents ==== === Requirements === [[Ordered pair]] === Related === [[Product type]]