Complex-number algebras {Banach algebra} can have norms. Norms can be absolute values. Product norm is less than or equal to product of norms. Real numbers, quaternions, or complex numbers form Banach algebra for multiplication when norm is absolute value. Banach algebra is associative. It can be commutative or non-commutative. It can have or not have identity element.
Only real numbers, complex numbers, quaternions, and octonions allow division {division algebra}.
Outline of Knowledge Database Home Page
Description of Outline of Knowledge Database
Date Modified: 2022.0225