**From:** Guy Steele (*Guy.Steele@Sun.COM*)

**Date:** Wed Nov 09 2005 - 10:43:33 CST

**Previous message:**Hans Aberg: "Re: Origin of the U+nnnn notation"**In reply to:**Philippe Verdy: "Re: Origin of the U+nnnn notation"**Next in thread:**Mark Davis: "Re: Origin of the U+nnnn notation"**Reply:**Mark Davis: "Re: Origin of the U+nnnn notation"**Messages sorted by:**[ date ] [ thread ] [ subject ] [ author ] [ attachment ]**Mail actions:**[ respond to this message ] [ mail a new topic ]

On Nov 8, 2005, at 10:52 PM, Philippe Verdy wrote:

*> From: "Guy Steele" <Guy.Steele@sun.com>
*

*>
*

*>>> A positive value too. Zero is both negative and positive.
*

*>>>
*

*>>>
*

*>> That is not the mathematically conventional use of those terms;
*

*>> rather, zero is neither negative nor positive. That is why we use
*

*>> the
*

*>> terms nonnegative (to mean "zero or positive") and nonpositive
*

*>> (to mean "zero or negative").
*

*>>
*

*>
*

*> That's the conventional mathematical use of the term positive, as I
*

*> learnt it. To say not null, I learnt "strictly positive", and never
*

*> "non-negative". This may be cultural differences here (I'm in
*

*> France, the terms were actually in French). But there are much
*

*> enough mathematical demonstrationsand definitions of variables that
*

*> use "positive" inclusively. We could also say "positive or null"
*

*> but this is generally not necessary.
*

*>
*

*> Okay, fair enough. (I am no expert in French, but of course
*

I respect the work and usage of French mathematicians.

I consulted a standard English dictionary, Merriam-Webster's

Tenth Collegiate, before making my remark, and the

Mathematical Dictionary by James and James agrees,

so I stand by my remarks about the technical meanings of

the terms in English. I refrain from citing the Wikipedia!)

ObUnicode: At http://www.unicode.org/Public/UNIDATA/UCD.html

we read the description of field 8 in UnicodeData.txt:

(8) If the character has the numeric property, as specified in

Chapter 4

of the Unicode Standard, the value of that character is

represented with

an positive or negative integer or rational number in this field.

[Yes, "an" positive, sic.] The author of this text seems to assume that

"positive or negative" includes zero, inasmuch as U+0030, for example,

has the value 0 in field 8. (I would have written "with a (possibly

signed)

integer or rational number" and then given the three examples of

U+0035 DIGIT FIVE having value 5, U+1946 LIMBU DIGIT ZERO having

value 0, and U+0F33 TIBETAN DIGIT HALF ZERO having value -1/2.)

--Guy Steele

**Next message:**Philippe Verdy: "Re: U+nnnn notation and normative identifiers."**Previous message:**Hans Aberg: "Re: Origin of the U+nnnn notation"**In reply to:**Philippe Verdy: "Re: Origin of the U+nnnn notation"**Next in thread:**Mark Davis: "Re: Origin of the U+nnnn notation"**Reply:**Mark Davis: "Re: Origin of the U+nnnn notation"**Messages sorted by:**[ date ] [ thread ] [ subject ] [ author ] [ attachment ]**Mail actions:**[ respond to this message ] [ mail a new topic ]

*
This archive was generated by hypermail 2.1.5
: Wed Nov 09 2005 - 10:45:29 CST
*