Date: Wed, 23 Jul 86 12:32 EDT From: Guy Steele <gls@Think.COM> One thing one can say is (OR FIXNUM (SIGNED-BYTE 20)), say, which a sufficiently clever compiler (heh, heh, heh) would understand to mean "use a fixnum, unless fixnums are less than 20 bits, in which case use at least 20 bits (whatever that takes)". What is the advantage of using this instead of (SIGNED-BYTE 20)?