Left arrows in witharrows package

Question

I wanted to make arrows going down by the left side of the equation when I use the witharrows package because sometimes is to much text on the right side. Sorry that I don't have en image to provide of what I want but I think de description it's enough, but if not I will modify the question adding a picture. Thanks to you all

Answer 1

As @F. Pantigny indicated, this is not built in to witharrows, but you can fake it by adding tikz={bend right, '} to the \Arrow options. The ' option causes the label to appear on the opposite side of the arrow. The only downside to this solution is that you must manually choose xoffset= (with a negative value) to move the arrow and label to the left the correct amount.

\documentclass{article}
\usepackage{witharrows}

\begin{document}

$\begin{WithArrows}
A & = \bigl((a+b)+1\bigr)^2 \Arrow[jump=2, xoffset=-5cm, tikz={bend right, '}]{we expand} \\
& = (a+b)^2 + 2(a+b) +1 \\
& = a^2 + 2ab + b^2 + 2a + 2b +1
\end{WithArrows}$

\end{document}

Answer 2

I'm the author of the package witharrows. At this time, it's not possible to draw arrows on the left side of the alignments with witharrows. However, it's a good suggestion. I will try to add that feature in witharrows.