8.2. Subroutines with Labeled Parameters

These subroutine types are a slightly different animal than the subroutines with positional parameters, but they have some of the same rules. The keywords on or to are required in the labeled-subroutine definition, followed by the name of the subroutine, and optionally a nonlabeled parameter called a direct parameter. If the subroutine has a direct parameter (it does not have to), then the subroutine name has to be followed by the keyword of or in:

On Square of intOne...