Re: New types; also opacity without passkeys [portable R4RS impl]

[Guillermo J. Rozas <gjr@martigny.ai.mit.edu>]

|   Date: Thu, 23 May 96 00:17 EDT
|   Cc: rrrs-authors@martigny.ai.mit.edu
|   Reply-To: jaffer@ai.mit.edu
|   From: Aubrey Jaffer <jaffer@martigny.ai.mit.edu>
|
|   I also tried to write such a program using only procedure opacity and
|   convinced myself that there was no way to redefine PAIR? or PROCEDURE?
|   so that new-types were disjoint from R4RS types while preserving
|   opacity.

I would like to understand this part.  If you allow redefinition of
existing procedures so that code distinct from this package uses the
new definition, you should be able to implement this, albeit
painfully.

This would not be a practical solution, but I'm not sure that this
proposal is based on practicality anyway.