HELP NULL                                             Steven Hardy, March 1982

    null(list) -> boolean;

This returns TRUE iff it is given an empty list.  An empty list is either NIL
or a pair whose FRONT is FALSE and whose BACK is a PROCEDURE.  This is what
the end of a dynamic list looks like once the procedure has returned TERMIN.

NULL expands dynamic lists if necessary.

NULL will cause a mishap if its argument is not a list.

See HELP * NIL, *PAIR, *PDTOLIST and TEACH * LISTS