+;;; the deprecated functions FIND-IF-NOT and POSITION-IF-NOT. We
+;;; didn't bother to worry about optimizing them, except note that on
+;;; Sat, Oct 06, 2001 at 04:22:38PM +0100, Christophe Rhodes wrote on
+;;; sbcl-devel
+;;;
+;;; My understanding is that while the :test-not argument is
+;;; deprecated in favour of :test (complement #'foo) because of
+;;; semantic difficulties (what happens if both :test and :test-not
+;;; are supplied, etc) the -if-not variants, while officially
+;;; deprecated, would be undeprecated were X3J13 actually to produce
+;;; a revised standard, as there are perfectly legitimate idiomatic
+;;; reasons for allowing the -if-not versions equal status,
+;;; particularly remove-if-not (== filter).
+;;;
+;;; This is only an informal understanding, I grant you, but
+;;; perhaps it's worth optimizing the -if-not versions in the same
+;;; way as the others?
+;;;
+;;; That sounds reasonable, so if someone wants to submit patches to
+;;; make the -IF-NOT functions compile as efficiently as the
+;;; corresponding -IF variants do, go for it. -- WHN 2001-10-06)