9.84.1 Top new questions this week

9.84.1.1 Infinite size nicematrix

https://tex.stackexchange.com/landing/r/digest?cta=question&id=705069

I am trying to write a nicematrix version of this tridiagonal (infinite size) matrix, as the pmatrix environment renders a very ugly version 
\begin{equation} 
\begin{pmatrix} 
-\lambda & \lambda ... 
[nicematrix]
 

asked by 20-sided-dice https://tex.stackexchange.com/landing/r/digest?cta=user&id=308999 Score of 7

answered by Sandy G https://tex.stackexchange.com/landing/r/digest?cta=user&id=125871 Score of 6

9.84.1.2 Adding arrows between two forests

https://tex.stackexchange.com/landing/r/digest?cta=question&id=705120

Here's my code: 
\documentclass[french, 12pt]{report} 
\usepackage[T1]{fontenc} 
\usepackage[utf8]{inputenc} 
\usepackage{lmodern} 
\usepackage[a4paper]{geometry} 
\usepackage{graphicx} % Required for ... 
[arrows] [forest]
 

asked by Caro https://tex.stackexchange.com/landing/r/digest?cta=user&id=311029 Score of 6

answered by Sandy G https://tex.stackexchange.com/landing/r/digest?cta=user&id=125871 Score of 9

9.84.1.3 How to avoid resetting macro definitions within a group/environment

https://tex.stackexchange.com/landing/r/digest?cta=question&id=705441

Here's the question: why does the following code reset the meaning of the \pgPtList control sequence when the group ends? 
\documentclass[12pt]{article} 
\begin{document} 
\begingroup 
\gdef\... 
[macros] [grouping]
                                                                                  

                                                                                  
 

asked by Kellen Brosnahan https://tex.stackexchange.com/landing/r/digest?cta=user&id=311046 Score of 5

answered by cfr https://tex.stackexchange.com/landing/r/digest?cta=user&id=39222 Score of 5

9.84.1.4 Reducing space before and after matrices

https://tex.stackexchange.com/landing/r/digest?cta=question&id=705425

I find the extra space added before and after matrices quite ugly: 
\documentclass{article} 
\usepackage{amsmath} 
\begin{document} 
$f\begin{pmatrix} 
1&2\\ 
3&4 
\end{pmatrix}.$ 
\end{... 
[spacing] [environments] [matrices]
 

asked by Zuy https://tex.stackexchange.com/landing/r/digest?cta=user&id=209090 Score of 5

answered by egreg https://tex.stackexchange.com/landing/r/digest?cta=user&id=4427 Score of 4

9.84.1.5 Beamer: how can I define circled numbered bullets without using enumitem package?

https://tex.stackexchange.com/landing/r/digest?cta=question&id=705345

I am using metropolis beamer theme. 
Could anyone help me create numbered items with circles around (see pic), but without using enumitem package, and compatible with XeLatex or Lualatex? 
I figured out ... 
[beamer]
 

asked by Eulerian https://tex.stackexchange.com/landing/r/digest?cta=user&id=229246 Score of 5

answered by cfr https://tex.stackexchange.com/landing/r/digest?cta=user&id=39222 Score of 5

9.84.1.6 Remove page number, if there is only one page in a section

https://tex.stackexchange.com/landing/r/digest?cta=question&id=705201

In my current project, I want to create worksheets that I can print out and distribute. To do this, I want to reset the page number for each worksheet, but only display the page number if the ... 
[header-footer] [page-numbering] [conditionals] [fancyhdr]
 

asked by Jim Ye https://tex.stackexchange.com/landing/r/digest?cta=user&id=208634 Score of 5

answered by egreg https://tex.stackexchange.com/landing/r/digest?cta=user&id=4427 Score of 2

9.84.1.7 How to recreate the "dangerous bend exercise" in TeXbook with `amsthm`

https://tex.stackexchange.com/landing/r/digest?cta=question&id=705255

I'm typing a document right now and have a warning theorem environment, created with amsthm. What intrigues me is that Knuth's The TeXbook managed to put the "dangerous bend" symbol in front ... 
[amsthm] [wrap]
 

asked by Gargantuar https://tex.stackexchange.com/landing/r/digest?cta=user&id=172890 Score of 4