newfun — add a name in the table of functions
newfun("function-name",nameptr) Utility function (for experts only). Adds the name "function-name"
in the table
of functions known to the interpreter. "nameptr" is an integer
1000*fun+fin where fun and fin is the internal coding of
the primitive "function-name".
This function is useful to associate a primitive to a routine
interfaced in "matusr.f" (fun=14).
Used with funptr and clearfun one can redefine a primitive
by a function with same name.