`:`

& `\colon`

¶Synopsis, one of:

: \colon

In mathematics, the colon character, `:`

, is a relation.

With side ratios \( 3:4 \) and \( 4:5 \), the triangle is right.

Ordinary LaTeX defines `\colon`

to produce the colon character
with the spacing appropriate for punctuation, as in set-builder notation
`\{x\colon 0\leq x<1\}`

.

But the widely-used `amsmath`

package defines `\colon`

for use
in the definition of functions `f\colon D\to C`

. So if you want
the colon character as a punctuation then use `\mathpunct{:}`

.