Doctrine:$\mathbb{K}$ (field)

Statement

$\mathbb{K}$ shall denote the field that is either the reals, so $\mathbb{K}:\eq\mathbb{R}$, or the complex numbers, so $\mathbb{K}:\eq\mathbb{C}$

Reasoning

Large swaths of functional analysis deal with something over either the reals or the complex numbers. $\mathbb{K}$ will denote - unless otherwise stated - the case where either may be substituted by the reader.

As seen in

• Books:Functional Analysis - Volume 1: A gentle introduction - Dzung Minh Ha