[no subject]

[Richard M. Stallman <RMS at MIT-AI>]

When Maclisp was changed to make the car and cdr of nil be nil,
it was partly to facilitate transporting Interlisp code,
but mostly because people thought it was an improvement.
I've found it saves me great numbers of explicit tests of nullness.
I don't think that any other improvements in data structure facilities
eliminate the usefulness of this.  I still appreciate it on the Lisp machine
despite the presence of defstruct and flavors.