In LaTeX, how does one get a colon instead of a full stop after a theorem?

Question

I want to know if there is some way to change that full stop after Definition. to a colon, i.e. to get Definition: (and for the other environments in the "definition" theoremstyle).

Answer 1

The easiest approach may be to define yourself a new style:

\newtheoremstyle{stylename} % name of the style to be used

{spaceabove}% measure of space to leave above the theorem. E.g.: 3pt

{spacebelow}% measure of space to leave below the theorem. E.g.: 3pt

{bodyfont}% name of font to use in the body of the theorem

{indent}% measure of space to indent

{headfont}% name of head font

{headpunctuation}% punctuation between head and body

{headspace}% space after theorem head; " " = normal interword space

{headspec}% Manually specify head

In this case, you would copy the existing definition style, and then change the value of headpunctuation.

Answer 2

AMS LaTeX should be included in any modern distribution. It (or the amsthm standalone package ([docs here PDF link!)) provides the \theoremstyle and \newtheoremstyle commands.