[XeTeX] linux libertine and number

[Ross Moore]

Hi Peter and François,

Sent from my iPad

On 29/12/2010, at 7:03 AM, Peter Dyballa <Peter_Dyballa at Web.DE> wrote:

> 
> Am 28.12.2010 um 19:44 schrieb François Patte:
> 
>> Multiply 5 by 7: $7\times 5 = 35$
> 
> With XeTeX and fontspec loaded you also load xunicode. So you can write as well:
> 
>    Multiply 5 by 7: 7 \texttimes{} 5 = 35

This will paint the correct symbols on the page, but does not guarantee that correct spacing is used, according to the conventions of mathematical typesetting. You may get this with some fonts, but there is no guarantee.

But more importantly, it does not encode anything about the meaning of these symbols, being used as a mathematical expression. Thus it does not help you if you later wish to adapt this to more complicated pieces of mathematics, nor does it allow for more sophisticated processors to embed tagging of this meaning within your document, for later extraction and proper interpretation in the context of an interactive electronic documents.

At some time in the future you will come to appreciate the value of having included this extra markup within your document source, by going the whole hog of writing:


>    Multiply $5$ by $7$: $5 \times 7 = 35$

or even using LaTeX delimiters, as:

     Multiply \(5\) by \(7\): \(5\times 7 = 35\)


>    
>    Multiply 5 by 7: 7 × 5 = 35
> 
> I see another problem here: Is 5 multiplied by 7 always equal to 7 × 5?

Good point. Although multiplication of integers is usually commutative, it is worthwhile to preserve the natural order, as an hint that in higher mathematical contexts this need not be the case.

But putting that reason aside, you will also find it easier to make multiple similar examples using different numbers by Copy/Paste/Edit , when the numbers occur in a consistent order within your expressions.

> 
> --
> Greetings
> 
>  Pete


Hope this helps,

       Ross