Le 27/07/2016 à 14:29, Frédéric Grosshans a écrit :
Le 27/07/2016 à 03:12, Robert Wheelock a écrit :
How do Arabs, Iranians, Afghans, Pakistanis, Urdu ... all write their
equivalents of common numerical fractions (consisting of a numerator,
a separator character, and a denominator)?!?!
Considering that Arabic written script reads from right to left (like
in Hebrew, Syro-Aramaic, and the fantasy language of Tsolyáni), would
they use a normal right-facing foreslash (1/2), a left-facing
backslash (1\2), or do they align numerator above|demoniator below a
horizontal fraction bar?!?!
Notice that these people would use the native Arabic-based digits in
them; nonewithstanding, the forms for |4 5 6| (and—sometimes—those
for |2 7|) do look quite different from the canonical Arabic forms.
The subject of modern arabic notation is quite complex, mixing RTL and
LTR consideration, as well as latin/arabic/greek/math mixing, with
several different approaches. A W3C document on this
(https://www.w3.org/TR/arabic-math/) enumerates 4 styles
(Moroccan/Maghreb/Machrek/Persian). It also contains the following
paragraph, which answers your question:
Finally, although stacked fractions are rendered the same way in
both European and Arabic, bevelled fractions in RTL Arabic will
appear, as one would expect, with the terms in RTL order, i.e. A
divided by B would appear as "B/A". In some locales, the preference
is for the slash to also be mirrored, as "B\A". For these cases, we
suggest that authors employ explicit markup using the REVERSE
SOLIDUS \
Looking at wikipedia (+ some google translate) gives you some examples :
If you look at the arabic wikipedia page on fraction
https://ar.wikipedia.org/wiki/%D9%83%D8%B3%D8%B1_(%D8%B1%D9%8A%D8%A7%D8%B6%D9%8A%D8%A7%D8%AA),
you will see the following sentence :
.كسر عادي (بسيط): هو الكسر الذي فيه البسط أصغر من المقام، أمثلة
10/6 ، 3/2 ، 5/4
According to google translate, all the numerators are smaller than the
denominator. A bit below, 2 4/5 is written :5/4 2, which is an
interesting mixture of RTL and LTR, as is often the case for numbers in
arabic script.
On the equivalent Persian wikipedia page
https://fa.wikipedia.org/wiki/%DA%A9%D8%B3%D8%B1, 3/4 is written ۳/۴,
that is LTR 3/4 in persian digits, even if the text is RTL. The opposite
convention is used.
The Hebrew (
https://he.wikipedia.org/wiki/%D7%A9%D7%91%D7%A8_(%D7%9E%D7%AA%D7%9E%D7%98%D7%99%D7%A7%D7%94)
) and Yiddish (
https://he.wikipedia.org/wiki/%D7%A9%D7%91%D7%A8_(%D7%9E%D7%AA%D7%9E%D7%98%D7%99%D7%A7%D7%94)
) equivalent pages seem to avoid the ambiguity by using exclusively
vertically stacked fraction (with the excetion of π/4 in the Hebrew page)
