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*To*: jaffer@ai.mit.edu*Subject*: R4RS compliance: negative numbers*From*: William D Clinger <will@ccs.neu.edu>*Date*: Tue, 14 May 1996 11:08:06 +0000*Cc*: rrrs-authors@martigny.ai.mit.edu, will@ccs.neu.edu*Organization*: Northeastern University*References*: <m0uJBQl-000alNC@jacal>*Reply-To*: will@ccs.neu.edu

I wrote: > I do not see why inexact numbers are any more misleading than > encoding "2 or more" as -3. Aubrey Jaffer wrote: > I do. R4RS compliant implementations are not required to support > inexact numbers, but they are required to support negative numbers. Four remarks: 1. I understand the argument that encoding "2 or more" as -3 may be less likely to run afoul of an implementation restriction than encoding it as 2.0. I do not understand the argument that encoding as -3 is less misleading than encoding as 2.0. 2. R4RS compliant implementations are not required to support negative numbers. Furthermore an implementation may be able to represent inexact negative numbers but not exact negative numbers. See R4RS 6.5.3. 3. This is 1996. As a practical matter, we can assume that almost all implementations will support inexact numbers, just as we assume that almost all implementations will support negative numbers. 4. As evidence for remark #3, I observe that these very assumptions have been made tacitly by those people who, for the past several days in this mailing list, have been defending the honor of Scheme's generic arithmetic against Matthias Blume's usual ML-is-better view. Will

**References**:**Re: Revised straw proposal for heuristic info***From:*Aubrey Jaffer <jaffer@martigny.ai.mit.edu>

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