P1788
Herewith, as a position paper, is the current version of the Neumaier-Pryce proposed decoration system, §4.8 of the current draft standard text v03.2.
It is part of §4, the Level 1 specification. Subclauses 4.1-4.7, on intervals, functions, expressions, required and recommended operations (elementary functions) have been extensively revised also; but Arnold and I wished to get the decoration part out for discussion alongside Nate's current position paper.
I think we and Nate have converged in many respects, though there are still differences. Points to note:
(1) We've added 2 decoration values ein and bnd.
- "ein" means "empty input box xx" as suggested by Dominique.
- Also the old "saf" is renamed "bnd" = "defined, continuous and bounded on xx" while "saf" just means "defined and continuous on xx".
This change is recent, and Arnold has taken on the task of verifying and revising the correctness proof for this new scheme.
(2) I have omitted a few parts of the decoration system, notably decorated intersection and union on which Arnold and I do not currently agree.
(3) I have included 4.8.6. "Bare object arithmetic with a threshold" which is an important concept originated by Nate. I haven't yet updated it to handle the new scheme with ein and bnd added.
Baker, would it be possible to have a discussion of Nate's and our papers alongside? What about voting on both simultaneously?
John