SEQUENCE-FUNCTIONS-EXCLUDE-ARRAYS (Version 2)

[David A. Moon <Moon@STONY-BROOK.SCRC.Symbolics.COM>]

Observation: some of the discussion appears to be assuming that
someone is proposing that

  (position 3 #2a((0 1 2)(3 4 5))) => (1 0)

As far as I can tell no one is proposing that.  My reading of
SEQUENCE-FUNCTIONS-EXCLUDE-ARRAYS:GENERALIZE (by Touretzky)
is that it proposes

  (position 3 #2a((0 1 2)(3 4 5))) => 3

and the other two options propose that it remains an error.

Vote: I mildly favor SEQUENCE-FUNCTIONS-EXCLUDE-ARRAYS:UNCHANGED as
being the least confusing to users, although either of the other two
proposals would be okay with me: if there is strong support for them,
I won't expend energy resisting it.