6.15.1 Top new questions this week

6.15.1.1 How can I draw dashed lines of this picture?

https://tex.stackexchange.com/landing/r/digest?cta=question&id=538458

I am trying to draw this picture 
I tried 
\documentclass[border=2mm,tikz]{standalone} 
\usepackage{tikz-3dplot} 
\usetikzlibrary{3dtools} 
\tikzset{intersection of line trough/.code args={#1 and  ... 
[tikz-3dplot]
 

asked by minhthien_2016 https://tex.stackexchange.com/landing/r/digest?cta=user&id=15080 15 votes

answered by SchrA~\[Paragraph]dinger's cat https://tex.stackexchange.com/landing/r/digest?cta=user&id=194703 20 votes

6.15.1.2 How can I type the symbol for usual topology $R_ (-) $ in LaTex?

https://tex.stackexchange.com/landing/r/digest?cta=question&id=538193

How could I type the symbol as shown in the picture below? 
I tried to use $\mathbb{R}_{(-)}$ instead, but the - inside can not touch the parenthesis on both sides. 
I want to create a horizontal line  ... 
[symbols] [code]
 

asked by Howardli621 https://tex.stackexchange.com/landing/r/digest?cta=user&id=209002 12 votes

answered by Sigur https://tex.stackexchange.com/landing/r/digest?cta=user&id=14757 11 votes

6.15.1.3 Drawing a 3D molecule in TikZ

https://tex.stackexchange.com/landing/r/digest?cta=question&id=537739

I'm trying to make a methane molecule in tikz-3d. All that's left is to make the "chemically correct" wedges and dashes. I tried with chemfig, but that only allows for a 2D molecule that pretends to  ... 
[tikz-pgf] [chemfig] [tikz-3dplot]
 

asked by methaneman https://tex.stackexchange.com/landing/r/digest?cta=user&id=212265 10 votes

answered by SchrA~\[Paragraph]dinger's cat https://tex.stackexchange.com/landing/r/digest?cta=user&id=194703 15 votes

6.15.1.4 Why curly braces are used when setting \spacefactor manually?

https://tex.stackexchange.com/landing/r/digest?cta=question&id=538127

In texbook.tex the following code is used to fake plain TeX format: 
Subsequent paragraphs {\it are\/} indented.*{\spacefactor=3000} 
(See?) The computer breaks a paragraph's 
Obviously, curly braces  ... 
[tex-core]
 

asked by Igor Liferenko https://tex.stackexchange.com/landing/r/digest?cta=user&id=70900 8 votes

answered by egreg https://tex.stackexchange.com/landing/r/digest?cta=user&id=4427 7 votes

6.15.1.5 Write a simple tree in LaTeX

https://tex.stackexchange.com/landing/r/digest?cta=question&id=538600

I would like to know how to write the following graph in LaTeX: 
I'm just a beginner in LaTeX, so I tried to follow this example, but I could not make it work. Using 
\begin{document} 
... 
[diagrams] [graphs] [trees]
 

asked by CorrA~\252a https://tex.stackexchange.com/landing/r/digest?cta=user&id=171231 6 votes

answered by Vincent https://tex.stackexchange.com/landing/r/digest?cta=user&id=201628 7 votes

6.15.1.6 Do Star Trek fonts exist for LaTeX?

https://tex.stackexchange.com/landing/r/digest?cta=question&id=538606

I've been looking for Star Trek fonts or symbols for LaTeX lately, but unfortunately I couldn't find any. Do any of you know if there is a Star Trek font or character set? 
[fonts]
                                                                                  

                                                                                  
 

asked by Fab2 https://tex.stackexchange.com/landing/r/digest?cta=user&id=211483 6 votes

answered by Sebastiano https://tex.stackexchange.com/landing/r/digest?cta=user&id=117876 7 votes

6.15.1.7 Symbol inside math operator

https://tex.stackexchange.com/landing/r/digest?cta=question&id=538370

I would like to define a math operator that looks a bit like this, which I mocked up in an image editor from the amsmath \square symbol: 
Sometimes there will be a different letter than lambda  ... 
[math-mode] [symbols]
 

asked by Nathaniel https://tex.stackexchange.com/landing/r/digest?cta=user&id=12461 6 votes

answered by Vincent https://tex.stackexchange.com/landing/r/digest?cta=user&id=201628 8 votes