How to write the set of quaternion numbers in Latex !

Set of quaternion numbers

In old books, classic mathematical number sets are marked in bold as follows

$\mathbf{H}$ is the set of quaternion numbers.

So we use the \ mathbf command. Which give:

$\mathbf{H}$ is the set of quaternion numbers.

You will have noticed that in recent books, we use a font that is based on double bars, this notation is actually derived from the writing of classic sets on the blackboard: indeed, on the blackboard we do not fill these sets, or it would take a ton of chalk !!! In Latex, we use the amsfonts package In the preamble we have:

\usepackage{amsfonts}

and \mathbb command

$\mathbb{H}$ is the set of quaternion numbers.

$\mathbb{H}$ is the set of quaternion numbers.