[texhax] Some questions on math mode

[Uwe Lück]

At 16:58 01.03.09, Philip TAYLOR wrote:
>P. R. Stanley wrote:
> > 3. The same document states that the \mathbb macro can be used for
> > displaying rationals reals and so forth. Again, What visual effects
> > does the mathbb have on the enclosing character.
>
>It creates "blackboard bold", which looks as if the same
>character had been rendered twice with a small displacement
>(horizontal) between the two instances.

Often it rather looks ... e.g. when the Blackboard Bold typeface was not 
available, one could try some "poor man's blackboard bold" by setting an 
uppercase `I' very tightly to the left of `R', `N' etc.
(real, natural ... numbers)

The proper typeface for the reals and the natural numbers is upright bold; 
this was imitated at blackboards by drawing some strokes twice ... and 
maybe especially in Germany this seems to be considered the standard 
canonical way of real numbers etc., it is very common in German textbooks. 
I.e. the blackboard version is considered correct and the original English 
typeface is considered misleading ... [right?]

> > I have come across
> > quite a few of those \math macros -- mathrm, mathtt and so on. It's
> > hard to know what they do or, more importantly, when they should be
> > used. Any tips would be most appreciated.
>
>In general, the "math" prefix simply indicates that the
>macro is intended for use in maths mode; the characters
>that follow indicate the intended effect, such as
>"rm" => "roman", meaning upright; "tt" -> "teletype",
>meaning monospaced and highly stylised.  It's a great
>shame that (as far as I know) no-one has yet reported
>a document from whence all of these things can be
>gleaned.

Hey! What about the LaTeX guides from the /doc/ directory!? usrguide.pdf 
Sec. 3.11, fntguide.pdf pp. 11f.

Hope This Is True -- Uwe.