

   FFuunnccttiioonn DDeeffiinniittiioonn

        function( arglist ) expr
        return(value)

   DDeessccrriippttiioonn::

        These functions provide the base mechanisms for defin-
        ing new functions in the R language.

   SSeeee AAllssoo::

        `args' and `body' for accessing the arguments and body
        of a function.  `debug' for debugging; `invisible' for
        `return(.)'ing invisibly.

   EExxaammpplleess::

        norm <- function(x) sqrt(x%*%x)
        norm(1:4)

        ## An anonymous function:
        (function(x,y){ z <- x^2 + y^2; x+y+z })(0:7, 1)

