multiple slot descriptions of the same slot in a DEFSTRUCT

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

    Date: 4 Jul 85 12:49 PDT
    From: Kahn.pa@Xerox.ARPA

    What does the following mean?

    (defstruct foo (a 0) (a 1))

    ....Along the same lines, is it an error when using the :include option to
    "over-ride" a default as follows

    (defstruct (bar (:include foo)) (a 2))
    ....

In my opinion both of these errors.  Each defstruct slot must have a
distinct name and it is beyond defstruct's scope to attempt to merge
together information from multiple sources about a single slot.  Let's
not get into object-oriented inheritance issues in something as
supposedly simple and straightforward as defstruct!