2.37.1 Top new questions this week

2.37.1.1 What does \do do?

http://tex.stackexchange.com/questions/331483/what-does-do-do

I saw some code using \do and I would like to understand it, which to me means finding out what exactly \do does. However, I haven't been able to find it in any sort of reference manual, and it is,  ...
 

- asked by interfect (23 votes), answered by Werner (16 votes)

2.37.1.2 Why does LaTeX throw an error without \begin document ?

http://tex.stackexchange.com/questions/331082/why-does-latex-throw-an-error-without-begindocument

Consider the following "Hello, World!" document. 
Hello, world! 
\end 
If you try to compile this using latex.exe, you get the error** 
! LaTeX Error: Missing \begin{document}. 
Okay, so on one hand,  ...
 

- asked by Jonathan Gleason (15 votes), answered by David Carlisle (20 votes)

2.37.1.3 Harry Potter symbols

http://tex.stackexchange.com/questions/331147/harry-potter-symbols

Good evening 
I have one unusual question. Are there some Harry Potter symbols in LaTeX (pictures below) ? 
Thanks for an answer.
 

- asked by A"\275ubomA~\[DiscretionaryHyphen]r MasaroviA"\215 (12 votes), answered by Heiko Oberdiek (19 votes)

2.37.1.4 Getting the catcode of a character assigned to a control sequence by \let

http://tex.stackexchange.com/questions/331690/getting-the-catcode-of-a-character-assigned-to-a-control-sequence-by-let

Given a control sequence \z that was defined like \let\z=z, how do you get the catcode the character z had at the time \z was defined? 
The obvious solution 
{\catcode`z=12 \global\let\z=z} 
...
 

- asked by siracusa (11 votes), answered by egreg (8 votes)

2.37.1.5 "just right" integral sign for tikz integrator block

http://tex.stackexchange.com/questions/331505/just-right-integral-sign-for-tikz-integrator-block

Goldilocks question: 
I want an integral sign and dt that looks good in a block diagram; the inline size looks too small and the displaystyle size looks too big. Is there any way I can scale it  ...
 

- asked by Jason S (9 votes), answered by egreg (3 votes)

2.37.1.6 Any easier way to draw lots of arrows in tikz?

http://tex.stackexchange.com/questions/331613/any-easier-way-to-draw-lots-of-arrows-in-tikz

I draw lots of block diagrams like this one (source below): 
The arrow drawing contains a lot of repetitive \draw[->] commands, and I'm wondering: is there any way to create a shortcut so that  ...
 

- asked by Jason S (8 votes), answered by Heiko Oberdiek (6 votes)

2.37.1.7 How are base TeX symbols defined?

http://tex.stackexchange.com/questions/331686/how-are-base-tex-symbols-defined

This is not so much a practical question as one of curiosity. I realize that if I want to define my own symbol, practically speaking, I would want to use \newcommand or something similar, and could  ...
 

- asked by Anomaly (8 votes), answered by siracusa (11 votes)