[Cfp-interest 2932] TS-4r augmented arithmetic terminology

[Jim Thomas]

Reviewing cfp4r-20230831, Robert Secord commented about Clause 7:

h usually contains the value, and t usually contains the error, so why aren't these variables named "v" and "e"?  what are h/t supposed to stand for, hat tip?

I responded:

h and t represent the head and tail of the result value. The tail is the error in the head as an approximation of the mathematical result, but regarding the head + tail as a wide precision result the tail isn’t an error.

Considering again, I think it would helpful if the TS said something about this terminology. How about inserting between the paragraphs:

The corresponding real type of the structure refers to the type of the members.

and 

The functions in this clause round to nearest with ties toward zero, ...

a new paragraph which says:

The functions in this clause use these structures to return a “head” value h and “tail” value t to represent an extra-precise result value given by h + t .

What do you think?

- Jim Thomas





-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.oakapple.net/pipermail/cfp-interest/attachments/20231023/e05b33fa/attachment.htm>