A simple question

[Russ Smith <smith@nrl-aic.ARPA>]

The "Cc"ed individual above uncovered an interesting difference between
interpreted and compiled CommonLisp on a Sun workstation that generated
a splurge of conversation here. In particular:

	(null (null '(a b c))

returns T when interpreted, but returns (a b c) when compiled. On
reading the **Sun** CommonLisp manual, this behavior, while possibly
despicable, is permitted. On reading THE CommonLisp manual, things are
not quite as obvious. Page 73 contains a definition for NULL that may
or may not say that NULL returns strictly T or NIL (see also page 82).

What's the poop?