LaTeX Typesetting Question

[flouran]

In LaTeX, to say that a is congruent to 1 (mod b), I use the \equiv command as such:
.

However, what is the LaTeX command for a is *not* congruent to 1 (mod b)? I thought it would be \nequiv, but it isn't.

Also, to show that a | b in LaTeX, I use the pipe symbol. What is the LaTeX command for a is *not* a divisor of b?

[Mini-Geek]

\not\equiv \not|

Or:

\cancel\equiv \cancel|

http://www.mersenneforum.org/mimetex.htm#not
I think the difference is that \cancel can be used on any arbitrary thing, while \not is only for single characters like \equiv, |, or 3. Not entirely sure about that, but it seems right from a quick test.

[flouran]

\not\equiv

worked for me, but

\not|

fails. I think that there is a command for the divisor (let's call it \cmd), and thus the code would be \not\cmd. I'll look into it more. I'll post back in a few minutes (or not) when I find it.

[Zeta-Flux]

I use \nmid, for not divides.

[flouran]

Originally Posted by Zeta-Flux

I use \nmid, for not divides.

That works!

[flouran]

In LaTeX, equations are autonumbered as (1), (2), (3),..., and so on. How do I make it such that every equation is labeled as such:
(a.b.c)
a = section number
b = subsection number
c = equation number within subsection

For instance, the 5th equation in the 2nd subsection of the 3rd section should be labeled as (3.2.5). I "googled" it, and it says I have to put

\numberwithin{equation}{subsection}

in the preamble, but that doesn't quite do the trick.

[flouran]

Also, I have an equation that is too long. For the sake of simplicity, let's say I have the equation,
x+y=5,
but that is too long.
Basically, how would I do it in LaTeX such that I have,
x+
y=5

In other words, how do I split an equation? Some of the guides I tried don't work....

[CRGreathouse]

Originally Posted by flouran

Also, I have an equation that is too long. For the sake of simplicity, let's say I have the equation,
x+y=5,
but that is too long.
Basically, how would I do it in LaTeX such that I have,
x+
y=5

In other words, how do I split an equation? Some of the guides I tried don't work....

I use

\[
\begin{split}
x&=-b/2\pm\\
&\sqrt{(b/2)^2-c}
\end{split}
\]

[Zeta-Flux]

You can also use \begin{eqnarray}\end{eqnarray}, or \begin{multline}\end{multline}, but I also like split.

[flouran]

Originally Posted by Zeta-Flux

You can also use \begin{eqnarray}\end{eqnarray}, or \begin{multline}\end{multline}, but I also like split.

So using the multiline command, to produce the output,
x+
y=5,

I would run:

\begin{multiline}
x+ \\
y=5
\end{multiline}

??

[Zeta-Flux]

Yep, except it is multline, not multiline. (That, and I like split better, but with multline you get equation numbers for each line.) I'll attach some of the LaTeX help files I have on my computer later tonight.