Btukfyl

I want to tag my equations with parallel aligned environment. The code is shown below

begin{equation*}

begin{aligned}

& bold{H}_1^topbold{x}_1^*+bold{K}_1^topbold{y}+bold{U}(omega_t)= bold{r}_1:\

& bold{A}_3^topbold{y}leq bold{b}_3:

end{aligned}

qquad

begin{aligned}

& boldsymbol{gamma}_1(omega_t), \

& boldsymbol{zeta}_1(omega_t), 

end{aligned}

end{equation*}

The output should be two aligned equations, and my goal is to tag them using tag.

I have tried to add tag to the first begin{aligned} block and the second block, but they all failed with an error saying "Package amsmath Error: tag not allowed here".

I have searched the forum but there is none regarding to the tag for double aligned equation. I need to use begin{equation*} instead of begin{equation} to allow tag, since I want to make my own tags.

Thank you in advance!

Gabriel

Maybe it is something like this you're after?

documentclass[10pt, a5paper]{book}

usepackage{mathtools, amssymb}

usepackage[showframe]{geometry} 

usepackage{tabularx}



makeatletter

newcommand*{compress}{@minipagetrue}

thispagestyle{empty}



begin{document}



noindentbegin{tabularx}{linewidth}{@{}>{hsize=1.2hsize compressarraybackslash}X @{qquad} >{hsize=0.8hsizecompressarraybackslash}X@{}}

{ begin{subequations}begin{align}

& mathbf{H}_1^topmathbf{x}_1^*+mathbf{K}_1^topmathbf{y}+mathbf{U}(omega_t)= mathbf{r}_1:\

& mathbf{A}_3^topmathbf{y}leq mathbf{b}_3:

end{align}

end{subequations}}

 &

{ begin{subequations}begin{align}

& boldsymbol{gamma}_1(omega_t), \

& boldsymbol{zeta}_1(omega_t),

end{align}

end{subequations}}

end{tabularx}



end{document}