Commercial minus as italic variant of division sign in German and Scandinavian context

[Leif Halvard Silli]

Asmus, 

I am not certain that commercial minus isn’t sometimes used as italics 
for the ”division sign minus”. For instance, when looking at my message 
in Firefox [1], the commercial minus looks like a “handwritten” variant 
of the division sign. I think it would be entirely possible to use a 
that way looking commercial minus in a Norwegian taxation formulary, 
for instance. (I attach a screenshot of it.) I suspect that it is a 
monospace Courier font. 

Also, I wonder about the claim in the General Punctuation section that 
commercial minus is used in taxation forms in Scandinavia and Germany. 
I would dearly like to see the evidence for that claim. I must say that 
I suspect that the use of the division sign in Norwegian taxation forms 
for this purpose have been counted in a s evidence for that claim - 
could it be that our ”straight commercial minus” was counted as, well, 
a commercial minus? Could it be that the wish to see oneself - or us - 
in the “German tradition”, made one draw the wrong conclusion about 
which character we use?

Anyway, when I spoke if 2052 as an italic version of 00F7, I meant in 
the, kind of, “mathematical” sense: Unicode for instance contains both 
MATHEMATICAL BOLD ITALIC CAPITAL A, and MATHEMATICAL BOLD CAPITAL A, 
and even if they are (I believe) used for different mathematical 
purposes, everyone sees and knows that they are variants of one and the 
same letter - the capital A. And also, in some contexts, one might be 
able to use a normal capital A instead of the mathematical ones.

The same knowledge is not present about 00F7 and 2052. The best would 
have been if the two characters shared a similar name. For instance, if 
00F7 got an additional, synonymous name, like STRAIGHT COMMERCIAL 
MINUS, or perhaps, better, COMMERCIAL HYPHEN-MINUS. Then the 
relationship would be clear - or at least clearer. Like MATHEMATICAL 
BOLD ITALIC CAPITAL A, and MATHEMATICAL BOLD CAPITAL A show, two 
characters do not need to be 100% synonymous just because their names 
only differs in a stylistic way, so to speak.

When reading Unicode, one is only left to guess about the relationship 
between 00F7 and 2052. For instance, 2052 is described in the general 
punctuation - and distinguished there from the ”normal” minus and 
hyphen-minus, whereas 0057 is not described there. A sentence, there, 
that said that, in some countries, it is actually the 00F7 and not the 
2052, that is used, would be very helpful and enlightenting.  Likewise, 
there is no description of 00F7 amongst the dashes/hyphens.

You wrote:

> Further, while italic (as well as oblique fonts) tend to slant the letter
> forms, there's not a universal, established practice of turning horizontal
> dashes into slashes to mark the alternation between roman and
> italic fonts. From that perspective, considering one the "italic"
> variant of the other also appears to be a non-starter.

Right. And I can only underline once more that I meant ”italic” as part 
of the name, see above.

You:

> However, it seems to be possible to establish that these two
> characters are indeed rather close variants: […]

Indeed.

> The choice of variant, though, is driven by context and tradition
> for a given type of document, not by choice of font style.
> And, the choice of using 2052 instead of hyphen-minus or minus
> is deliberate and conscious, making it an alternate spelling rather
> than an alternate "glyph".

Well, yes.

> If 00F7 can be used to stand in as a marked 2011, as claimed in
> the Unicode namelist annotation then that use is clearly NOT
> as a variant of 2052, because 2011 does not have
> any connotations of negation.

It is an argument for seeing 00F7 as (also) a hyphen-minus variant, no?

> That means the semantic
> relations between 00F7 and 2052 only partially overlap, which
> is yet another indication that thinking of one as a font-style
> variant of the other is not particularly helpful - even if the
> ultimate origin may have derived from the same sign.
> 
> At this stage of the game, they are properly disunified,
> just as i and j or u and v.

I am not really arguing for their unification - which anyhow is 
impossible, if I have understood the stability rules of Unicode. 
(Whereas an *additional* name is not ruled out, if I got it right.) I 
am ”only” arguing that Unicode takes information that clearly links the 
two together. As it is today, no one seems to realize how commercial 
minus relates to “division sign minus”.


[1] http://unicode.org/pipermail/unicode/2014-January/000013.html
[2] attachment of the file “screenshot-of-minuses.png" 
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Leif Halvard Silli

Asmus Freytag, Wed, 15 Jan 2014 23:17:46 -0800:
> I find it unhelpful to consider 2052 as the italic variant of 00F7, and
> further find the "evidence" for that not all that germane.
> 
> Both are variants of the "-" sign, and so ipso facto are variants of
> each other.
> 
> However, to identify something as "italic" to me would require that
> one form is used in the context of italic fonts, while the other is not.
> 
> I cannot see anything supporting that interpretation in the "evidence"
> adduced below.
> 
> On the contrary, you would expect both forms available in sans-serif
> and typewriter fonts (those being perhaps the most common for
> accounting), and perhaps also roman.
> 
> Further, while italic (as well as oblique fonts) tend to slant the letter
> forms, there's not a universal, established practice of turning horizontal
> dashes into slashes to mark the alternation between roman and
> italic fonts. From that perspective, considering one the "italic"
> variant of the other also appears to be a non-starter.
> 
> However, it seems to be possible to establish that these two
> characters are indeed rather close variants: both are used
> to visually emphasize the minus sign by means of decorating
> it with a pair of dots. And both are employed in situations that
> are have a large semantic overlap. (Not surprisingly, because their
> meaning is based on the minus sign).
> 
> The choice of variant, though, is driven by context and tradition
> for a given type of document, not by choice of font style.
> And, the choice of using 2052 instead of hyphen-minus or minus
> is deliberate and conscious, making it an alternate spelling rather
> than an alternate "glyph".
> 
> If 00F7 can be used to stand in as a marked 2011, as claimed in
> the Unicode namelist annotation then that use is clearly NOT
> as a variant of 2052, because 2011 does not have
> any connotations of negation. That means the semantic
> relations between 00F7 and 2052 only partially overlap, which
> is yet another indication that thinking of one as a font-style
> variant of the other is not particularly helpful - even if the
> ultimate origin may have derived from the same sign.
> 
> At this stage of the game, they are properly disunified,
> just as i and j or u and v.
> 
> A./
> 
> 
> 
> 
> On 1/15/2014 7:43 PM, Leif Halvard Silli wrote:
>> Thanks to our discussion in July 2012,[1] the Unicode code charts now
>> says, about 00F7 ÷ DIVISION SIGN, this:
>> 
>>    “• occasionally used as an alternate, more visually
>>       distinct version of 2212 − {MINUS SIGN} or 2011 ‑
>>       {NON-BREAKING HYPHEN} in some contexts
>>          [… snip …]
>>     → 2052 ⁒ commercial minus sign”
>> 
>> However, I think it can also be added somewhere that commercial minus
>> is just the italic variant of ”division minus”. I’ll hereby argue for
>> this based on an old German book on ”commercial arithmetics” I have
>> come accross, plus what the the July 2012 discussion and what Unicode
>> already says about the commercial sign:
>> 
>> FIRST: IDENTICAL CONTEXTS.
>> 
>>     German language is an important locale for the Commercial Minus. In
>> German, the Commercial minus is both referred to as ”kaufmännische
>> Minus(zeichen)” and as "buchhalterische Minus" (”Commercial Minus
>> Character” and ”Bookkeeper Minus”). And, speaking of ”division minus”
>> in the context I know best, Norway, we find it in advertising
>> (commercial context) and in book keeping documentation and taxation
>> forms. Simply put, what the Unicode 6.2 ”General Punctuation” section
>> says about Commercial Minus, can also be said about DIVISION SIGN used
>> as minus: «U+2052 % commercial minus sign is used in commercial or tax
>> related forms or publications in several European countries, including
>> Germany and Scandinavia.» So, basically and for the most part, the
>> commercial minus and the ”division sign minus” occur in the very same
>> contexts, with very much the same meaning. This is a strong hint that
>> they are the same character.
>> 
>> SECOND: GERMAN USE OF DIVISION SIGN FOR MINUS IN COMMERCIAL CONTEXT.
>> 
>>     Is there any proof that German used both an italics variant and a
>> non-italics variant of the “division minus”? Seemingly yes. The book
>> “Kaufmännische Arithmetik” (“Commercial arithmetics”) from 1825 by
>> Johann Philipp Schellenberg. By reading section 118 «Anhang zur
>> Addition und Subtraction der Brüche» [”Appendix about the addition and
>> subtraction of fractions”]) at page 213 and onwards,[2] we can conclude
>> that he describes as “commercial” use of the ÷ ”division minus”, where
>> the ÷ signifies a _negative remainder_ of a division (while the plus
>> sign is used to signify a positive remainder). Or to quote, from page
>> 214: «so wird das Fehlende durch das [Zei]chen ÷ (minus) bemerkt, und
>> bei Berechn[nung der Preis der Waare abgezogen» [”then the lacking
>> remainder is marked with the ÷ (minus) and withdrawn when the price of
>> the commodity is calculated”]. {Note that some bits of the text are
>> lacking, I marked my guessed in square brackets.} I did not find (yet)
>> that he used the italic commercial minus, however, the context is
>> correct. (My guess is that the italics variant has been put to more
>> use, in the computer age, partly to separate it from the DIVISION SIGN
>> or may be simply because people started to see it often in handwriting
>> but seldom in print. And so would not have recognized it in the form of
>> the non-italic division sign.)
>> 
>> THIRD: IDENTICAL INTERPRETATION
>> 
>> The word “abgezogen” in the above quote is interesting since the Code
>> Charts for 2052 ⁒ COMMERCIAL MINUS cites the related German word
>> “abzüglich”. And from the Swedish context, the charts quotes the
>> expression “med avdrag”. English translation might be ”to be withdrawn”
>> or ”with subtraction/rebate [for]”. Simply put, we here see the
>> commercial meaning.
>> 
>> WHAT ABOUT COMMERCIAL MINUS AS “CORRECT” SIGN  IN SCANDINAVIAN SCHOOLS?
>> 
>> UNICODE 6.3 notes that in some European (e.g. Finnish, Swedish and
>> perhaps Norwegian) traditions, teachers use the Commercial Minus Sign
>> to signify that something is correct (whereas a red check mark is used
>> to signify error). If my theory is right, that commercial minus and
>> division sign minus are the same signs, how on earth is that possible?
>> How can a minus sign count as positive for the student?
>> 
>> The answer is, I think, to be found in the Code Chart’s Swedish
>> description ("med avdrag"/"with subtraction/rebate"). Because, I think
>> that the correct understanding is not that it means "correct" or "OK".
>> Rather, it denotes something that is counted in the customer/student’s
>> favor. So, you could say it it really means "slack", or "rebate".  So
>> it really mans ”good answer“. It is a ”rebate” that the student
>> rightfully deserves.
>> 
>> FOURTH: A DEEPER MEANING
>> 
>> If we look at it from a very high level, then we can say that the
>> division minus is used to signify something that is the result of a
>> calculation - such as a price, an entry in bookkeeping or, indeed, a
>> character/mark/point/score in a (home)work evaluated by a teacher.
>> Whereas the ”normal” minus sign is used to when we represent negative
>> data. For example, in taxation, all the numbers one reports, is the
>> result of some calculation. Likewise, when a teach ticks of an answer
>> as “good answer”, then it is because the teacher has evaluated (a.k.a.
>> ”calculated”) the answer and found it to be good and that the student
>> has calculated correctly/well.
>> 
>> CIRCUMSTANCIAL EVIDENCE
>> 
>> The commercial minus looks like a percentage sign. And also, in
>> programming, e.g. JavaScript, the percentage sign is often used for the
>> modulo operator - which is an operator that finds the dividend of a
>> division.
>> 
>> Hence, when we take all this together, I believe we have to conclude
>> that the COMMERCIAL MINUS is just the italic variant of the DIVISION
>> SIGN.
>> 
>> PS: For more German documentation of this custom, it would probably be
>> wise to research books about bookkeeping as well as ”commercial
>> arithmetics”. I also have a suspicion that it would be worth
>> investigation contexts where modulo/division remainders operations are
>> found - for instance, in calendar calculations.
>> 
>> [1] http://www.unicode.org/mail-arch/unicode-ml/y2012-m07/0053.html
>> [2]
>> https://archive.org/stream/kaufmnnischeari00schegoog#page/n229/mode/2up
>