Vienna proposal for interval standardization

This document contains a detailed proposal for a future IEEE 1788 standard on interval arithmetic. It is written in a form that should be not too difficult to transform into a formal, complete and fully precise document specifying the standard to be. Part 1 contains a concise summary of the basic assumptions (some of which may be con- troversial) upon which the remaining document is based. The items in Part 1 are grouped such that separate voting on each issue is meaningful. Parts 2-5 specify the internal representation of intervals and the operations defined on them. Part 6 specifies the external representation of intervals and the conversion between internal and external representations. Part 7 is optional and discusses useful modifications of the directed rounding behavior specified in the IEEE 754-2008 standard that would simplify an implementation of the proposed standard. This final version incorporates many suggestions and corrections by the people mentioned above. In particular, comprehensive discussions with Michel Hack, who read and com- mented in detail many intermediate versions, had a strong influence on this proposal.