I am trying to get the following output (this is just written using Google Docs):
I find that align* doesn't work here as there is no = present. Further, I would like this to be centralised, so I have not tried using flalign* (as my understanding is that flalign* can only be used to align equations to the left-hand-side).
Any assistance would be much appreciated.
Using align like this should be working:
\documentclass{article}
\usepackage{amsmath}
\begin{document}
\begin{align*}
& \gcd(a,b) \mid a \ and \ b \\
\Rightarrow & \gcd(a,b) \mid ax + by \\
\Rightarrow & \gcd(a,b) \mid d
\end{align*}
\end{document}
When I compile it, it is well centered and looks like your picture. Hope this helps
You can use an align, even without =.
\documentclass{article}
\usepackage{amsmath}
\begin{document}
\begin{align}
& \gcd(a, b) ,|, a \text{ and } b \
\Rightarrow & \gcd(a, b) ,|, ax + by \
\Rightarrow & \gcd(a, b) ,|, d
\end{align}
\end{document}
It does work. Align the | symbol:
\documentclass{article}
\usepackage{amsmath}
\begin{document}
\begin{align}
\gcd(a, b) & \mid a, b \
\implies \gcd(a, b) & \mid ax + by \
\implies \gcd(a, b) & \mid d
\end{align}
\end{document}
These lines can be produced using the "eqnarray"-environment:
\begin{eqnarray*}
gcd(a,b) &|& a and b
=>gcd(a,b) &|& ax + by
=>gcd(a,b) &|& d
\end{eqnarray*}
Use the asterix (*) to suppress the numbering of the equations and the sign "&" on both of the sign which you want to center around.
