In functional analysis and related areas of mathematics, a BK-space or Banach coordinate space is a sequence space endowed with a suitable norm to turn it into a Banach space. All BK-spaces are normable FK-spaces.
Examples
The space of convergent sequences <math>c,</math> the space of vanishing sequences <math>c_0,</math> and the space of bounded sequences <math>\ell^\infty</math> under the supremum norm <math>\|\cdot\|_{\infty}.</math>