5.26.3 Can you answer these questions?

5.26.3.1 Strange XOR behaviour with polyglossia and arabxetex [memoir]

https://tex.stackexchange.com/landing/r/newsletter?cta=question&id=501897

I'm getting a strange behaviour when loading polyglossia and arabxetex together, and enabling \setotherlanguages{arabic}. 
MWE: 
\documentclass[a4paper,12pt,twoside]{memoir} 
\usepackage{xcolor} 
... 
[memoir] [polyglossia] [arabic] [arabxetex]
 

asked by imdk4242 https://tex.stackexchange.com/landing/r/newsletter?cta=user&id=192642 1 vote

5.26.3.2 How to do long division of an angle in degrees

https://tex.stackexchange.com/landing/r/newsletter?cta=question&id=501910

Is there a way to display the basic operations with angles in degrees, just like xlop does with integers? 
For example, with integers we use: 
\documentclass{article} 
\usepackage{xlop} 
... 
[arithmetic] [xlop] [degrees]
 

asked by Ulysses https://tex.stackexchange.com/landing/r/newsletter?cta=user&id=72388 1 vote

5.26.3.3 LuaLaTeX not outputting ligatures in Helvetica Neue TrueType Collection

https://tex.stackexchange.com/landing/r/newsletter?cta=question&id=501715

Consider the following MWE: 
\documentclass{article} 
\usepackage{fontspec} 
\setmainfont{HelveticaNeue.ttc}[ 
UprightFeatures = {FontIndex=0} 
] 
\begin{document} 
ff fi fl ffi ffl 
\end{document} 
... 
[fonts] [luatex] [fontspec] [ligatures] [luaotfload]
 

asked by solisoc https://tex.stackexchange.com/landing/r/newsletter?cta=user&id=169189 1 vote