NAME
functionp() - determine whether or not a given variable is a function pointer.
SYNOPSIS
int functionp(mixed arg);
DESCRIPTION
Return 1 if `arg' is a function pointer and zero (0) otherwise. Function
pointers are variables of type 'function' and are constructed as follows:
f = (: obj, func :);
SEE ALSO
stringp(3)
, pointerp(3)
, objectp(3)
, function