3.8.1 Top new questions this week

3.8.1.1 What does \mathgroup mean? How to use it?

http://tex.stackexchange.com/questions/354661/what-does-mathgroup-mean-how-to-use-it

I have a paragraph of lots of vectors symbols, so I need to type something like: 
$\mathbf{a}\cdot\mathbf{b}=\frac{\mathbf{a}+\mathbf{b}}{\mathbf{a}\cdot\mathbf{v}}$ 
(just an example). 
It is so  ...
 

- asked by Eric (16 votes), answered by egreg (22 votes)

3.8.1.2 spacing between math and \right closing delimeter with LuaTeX and unicode-math

http://tex.stackexchange.com/questions/354477/spacing-between-math-and-right-closing-delimeter-with-luatex-and-unicode-math

I noticed that the spacing between math inside a pair of delimiters using \left and \right and the closing delimiter (the one with \right) itself is sometimes wrong when using LuaTeX and unicode-math.  ...
 

- asked by Marco (11 votes), answered by David Carlisle (9 votes)

3.8.1.3 How to disable percent-encoding in URLs?

http://tex.stackexchange.com/questions/355136/how-to-disable-percent-encoding-in-urls

I try to add a unicode URL into the bibliography and LaTeX automatically converts the cyrillyc letters into percent-encoding. I found that hyperref is responsible for this, but I found no way to  ...
 

- asked by Himura (10 votes), answered by Ulrike Fischer (9 votes)

3.8.1.4 Rewriting the standard classes with xparse

http://tex.stackexchange.com/questions/354494/rewriting-the-standard-classes-with-xparse

I practised with xparse. I rewrote the definition of \part. When I try the following code everything works: 
\documentclass{book} 
\usepackage{xparse} 
\newcounter{spart}% makes hyperref work 
...
 

- asked by user125730 (10 votes), answered by egreg (10 votes)

3.8.1.5 Theta hat dot: upright and bold

http://tex.stackexchange.com/questions/354919/theta-hat-dot-upright-and-bold

I've had endless problems trying to get bold, upright theta symbol, with a bold hat on top, and an ordinary dot on top of that. 
I got most of the way, minus the dot, using the following code: (I got  ...
 

- asked by Jean-Jacq du Plessis (9 votes), answered by Mico (8 votes)

3.8.1.6 Misaligned math expression inside subfig

http://tex.stackexchange.com/questions/355040/misaligned-math-expression-inside-subfig

I am trying to get the matrix to align with the figures,  but I can't figure out how to do it. The matrix always appears much lower than the figures. 
\documentclass{article} 
...
 

- asked by kristoh (8 votes), answered by Heiko Oberdiek (8 votes)

3.8.1.7 Some LuaTeX unicode characters not working

http://tex.stackexchange.com/questions/354443/some-luatex-unicode-characters-not-working

I know that I can type unicode characters by number in LuaTeX with ^^^^00a9 for example. Works for the copyright symbol. 
I can't get it to work though for arbitrary symbols like ^^^^2764 (heart) or  ...
 

- asked by Tim T (8 votes), answered by Paul Gaborit (16 votes)