Write text next to series of equalities

As suggested by John Kormylo one can do this.

documentclass{article}
usepackage{amsmath}
usepackage{xcolor}
begin{document}
    begin{align*}
        (xcirc y) circ (xcirc y) & = xcirc (ycirc x)circ y & &textnormal{$circ$ is color{blue}{associative}}
        & = x circ (xcirc y) circ y & &textnormal{$x$ and $y$ textcolor{blue}{commute}}
        & = (xcirc x) circ (y circ y) & &textnormal{$circ$ is textcolor{blue}{associative}}
        & = e_G circ e_G & & textnormal{$x$ and $y$ are textcolor{blue}{self-inverse}}
        & = e_G & & textnormal{Definition of textcolor{blue}{Identity Element}}
    end{align*}
end{document}