Indeed, one of us must be confused.

[Scott E. Fahlman <Fahlman at Cmu-20c>]

KMP suggests that "on the LispM there really will not be any vectors and
that intuitively the right thing is for nothing to claim to be a
vector."  All I can say is that my intuition differs from his on this
issue.  I think it is perfectly intuitive to think of vectors on some
implementations as being limited creatures, and that the LispM is a
superset in that its vectors can do some extra tricks.  In KMP's
proposal, it is the implementations that "support vectors" that are the
superset -- that seems strange to me.

As KMP points out, you cannot debug protable Common Lisp code completely
on a system that provides a superset of the Common Lisp functionality,
unless a degraded "compatibility-mode" is provided or perhaps some sort
of portability checker in the compiler.  This is not a new sitution --
it occurs wherever Common Lisp has stopped short of providing the full
Zetalisp features.  There are many such cases already, and this one
doesn't bother me.

So the "RPG memorial" proposal still looks OK to me, as it is.