[Tex/LaTex] Aligning equations with left and right comment

align

I'd like to align multiple equations below each other such that the central operator is always centered, but have a column for commenting on the right and a column for \iff-arrows and \Rightarrow-arrows on the left.
This is as far as I got:

\begin{align*}
&& A &\aprecdot \mathfrak{G}^{\signminus 1}_1(\mathfrak{G}(C))
    && \text{by \eqref{eq:C}} \\
\iff && \mathfrak{G}(A) &\cprecdot \mathfrak{G}(\mathfrak{G}^{\signminus 1}_1(\mathfrak{G}(C))) 
    && \text{by \eqref{eq:D}} \\
\iff && \mathfrak{G}(A) &\cprecdot \mathfrak{G}(C) 
    && \text {by axiom 1.} \\
\iff && \mathfrak{G}^{\signminus 1}_1(\mathfrak{G}(A)) &\aprecdot \mathfrak{G}^{\signminus 1}_1(\mathfrak{G}(C)) \\
\iff && A &\aprecdot B
\end{align*}

It works quite well, but the problem is that if I have several of these below each other, separated by text, this looks ugly because the column widths are quite different. Therefore I want to put the \iff-arrows to the left border and the comments, while left-aligned, at a fixed distance from the right border. How can I do this?

Thanks in advance.

Best Answer

I agree with A. Ellet. flalign is probably the best option if you are trying to have any kind of commentary. Here is a more basic example which just solves for a specific variable:

\documentclass{article}

\usepackage{amsmath}
\usepackage{amssymb}

\begin{document}

\begin{flalign*}
&& d &= v_{o}t + \frac{1}{2}at^{2} && \text{A kinematic equation} \\
\Rightarrow && d - v_{o}t &= \frac{1}{2}at^{2} && \text{Another comment} \\
\Rightarrow && \frac{2(d - v_{o}t)}{a} &= t^{2} && \text{One here too} \\
\Rightarrow && \sqrt{\frac{2(d - v_{o}t)}{a}} &= t && \text{Solved for $t$}
\end{flalign*}

\end{document}

This produces Screenshot Of Output

I'm not really sure how to get the comments and arrows closer to the overall equation though.

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