Re: Lispm SXHASH loses worse than you think.

[BAK at MIT-AI (William A. Kornfeld)]

Another problem with the Lispm SXHASH is due to its using LOGXOR.  The
result of this is that pairs of things (pairs of changes) are ignored.

Examples:

(SXHASH '(A))   =   (SXHASH '(X A X))   =   (SXHASH '(X X A X X))

(SXHASH '(PLUS FOO BAR))  =   (SXHASH '(PLUS TV-FOO TV-BAR))