7.21.1 Top new questions this week

7.21.1.1 Why does plain TeX set \tolerance larger than \pretolerance?

https://tex.stackexchange.com/landing/r/digest?cta=question&id=590752

When TeX breaks a paragraph into lines, it makes three passes. In the first pass, TeX tries to break the paragraph without hyphenation, during which it makes sure that no line has a badness (from glue ... 
[line-breaking] [tex-core]
 

asked by Ruixi Zhang https://tex.stackexchange.com/landing/r/digest?cta=user&id=164314 14 votes

answered by ShreevatsaR https://tex.stackexchange.com/landing/r/digest?cta=user&id=48 5 votes

7.21.1.2 Best way to write $\lim^1$

https://tex.stackexchange.com/landing/r/digest?cta=question&id=591014

The expression $\lim^1$ is often used in homological algebra, where the superscript always appears on the top-right of the \lim-term, never immediately above it. I run into issues when I want to ... 
[spacing]
 

asked by SvanN https://tex.stackexchange.com/landing/r/digest?cta=user&id=135061 12 votes

answered by Steven B. Segletes https://tex.stackexchange.com/landing/r/digest?cta=user&id=25858 6 votes

7.21.1.3 What is wrong with the $f$ symbol?

https://tex.stackexchange.com/landing/r/digest?cta=question&id=591007

I came across some spacing glitches when I use the f symbol (I'm not having similar weirdness with most other symbols).  Here's a very simple MWE to show the issue: 
\documentclass[11pt,letterpaper,... 
[math-mode] [spacing] [symbols] [amsmath]
 

asked by Cham https://tex.stackexchange.com/landing/r/digest?cta=user&id=139556 11 votes

answered by egreg https://tex.stackexchange.com/landing/r/digest?cta=user&id=4427 17 votes

7.21.1.4 Four TeX processors (as described in TeX by Topic)

https://tex.stackexchange.com/landing/r/digest?cta=question&id=591217

I started reading TeX by Topic by Victor Eijkhout. He starts from describing four engines: 
The input processor. This is the piece of TeX that accepts input lines from the file system 
of whatever ... 
[tex-core]
 

asked by facetus https://tex.stackexchange.com/landing/r/digest?cta=user&id=29546 10 votes

answered by facetus https://tex.stackexchange.com/landing/r/digest?cta=user&id=29546 1 vote

7.21.1.5 An Exquisite Mathematical Font

https://tex.stackexchange.com/landing/r/digest?cta=question&id=591148

EDIT: The extension to this question, Replicating an Exquisite Font, is a means to the same end with the construction of such a font being the primary goal. 
I've recently been wondering: "where ... 
[fonts] [math-fonts]
 

asked by Alexander Conrad https://tex.stackexchange.com/landing/r/digest?cta=user&id=238901 8 votes

answered by palopezv https://tex.stackexchange.com/landing/r/digest?cta=user&id=1152 9 votes

7.21.1.6 How do you do a "staircase align" in Latex?

https://tex.stackexchange.com/landing/r/digest?cta=question&id=590738

I want to create something like 
or 
where the = is aligned with the last character of the previous equation. But I'm not sure how to make this work. 
I've tried, 
\begin{align} a = b & \\ 
... 
[math-mode] [align] [alignat]
                                                                                  

                                                                                  
 

asked by Procyonic https://tex.stackexchange.com/landing/r/digest?cta=user&id=155226 8 votes

answered by Steven B. Segletes https://tex.stackexchange.com/landing/r/digest?cta=user&id=25858 16 votes

7.21.1.7 My old rule does not work anymore with the latest version of arara

https://tex.stackexchange.com/landing/r/digest?cta=question&id=591664

I have a rule which worked with the previous version of arara: 
!config 
# Open the every <filename>.<format> that can be opened 
# The default for <filename> is the current file. 
# The ... 
[errors] [arara]
 

asked by CarLaTeX https://tex.stackexchange.com/landing/r/digest?cta=user&id=101651 6 votes

answered by Paulo Cereda https://tex.stackexchange.com/landing/r/digest?cta=user&id=3094 8 votes