**Blackboard bold** is probably the most common way of denoting the "standard" number sets: the natural numbers, the integers and so on. In AMS-LaTeX, you use the `\mathbb{...}`

command to obtain them; the ConTeXt way is the `\blackboard{...}`

command. Also, the following commands are defined:

`\naturalnumbers`

`\integers`

`\rationals`

`\reals`

`\complexes`

as well as `\primes`

for blackboard bold P.

See also Doublestroke for an alternative to the msbm font.