[XeTeX] Font variant selection in Fontspec/Mathspec options incomplete

[Tobias Schoel]

Am 13.11.2010 12:49, schrieb Christian Schmidt:
> I wasn't aware about this issue. In normal text mode, italic and bold
> font selections work complementary... so I expected the same behavior in
> math mode too. I can't really understand these differing approaches.

Maybe, I am too bold answering, but I try nevertheless:

Different fonts resp. font styles are not used as emphasis or stylistic 
features in math mode. They carry semantic meaning. A bold N is 
something totally different from a regular N which is something totally 
different from a curly N which is something totally different from 
fraktur N. (These meanings may depend on context but in each context 
they are different. An example:

regular N: some (probably natural) number [e.g. absolute frequency or 
sample count]

bold N: a matrix named N

curly N: the kernel function of matrices

fraktur N / double struck N: set of natural numbers
)

So when I type \mathbf{N} I usually refer to a matrix named N, because a 
bold italic N might have some different meaning. (Though bold italics 
aren't used often.)

Math isn't always typed in italics. The meaning shouldn't depend on the 
stylistic circumstances. \mathbf{N} should have the same meaning in each 
context. So \mathbf{N} should always yield a bold non-italic N, 
regardless of the style of regular math.

bye

Toscho