The recommended way to invoke usage is to use a double question mark (??). The recommended way to invoke example is to use a triple question mark (???).

When invoking info, usage, example, or related using the function call syntax, Maple keywords (reserved words) must be enclosed in back-quotes.  For example, info(quit) causes a syntax error. Use info(`quit`) instead. When using the double or triple question mark syntax, no quotes are required.

$\mathrm{info}\left(\mathrm{int}\right)$

$\mathrm{usage}\left(\mathrm{diff}\right)$

$\mathrm{usage}\left(''sin''\right)$

$\mathrm{example}\left(\mathrm{plot}\left[\mathrm{parametric}\right]\right)$

$\mathrm{example}\left(''plot''\right)$

$\mathrm{related}\left(\mathrm{help}\right)$