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Motion 4



Dear members of the working group.
I propose the following motion.
John Pryce


===Motion P1788/M0003.01_Set_of_reals===
Proposer: John Pryce
Seconder: Dan Zuras

===Motion text===
P1788 says nothing about interval arithmetic on computer architectures that
are not 754-compliant.



===Rationale===
This motion is in support of KISS: "Keep It Simple, Stupid". It delimits 1788's responsibilities. It limits and simplifies our work in that our design decisions may freely assume the existence of NaN (and possible payload), the sign-exponent-significand layout, etc.

The question has been asked: If 1788 says nothing about non-754 architectures, does that mean that any interval implementation on such an architecture is automatically 1788-compliant?

This IMO is not a question about the motion but about what standard- compliance means. My understanding is that an implementation is compliant with a standard iff it obeys every normative clause in that standard.

Therefore it is *conceivable* that an implementation on a non-754 machine can be made 1788-compliant -- in the unlikely case that 1788 actually makes no 754-specific decisions!

In practice, presumably, that will not be so. Then, someone may consider that 1788 should define a "lower tier" of compliance for intervals on non-754 machines. They may wish to move a suitable amendment to this motion.