HPSG Head-Complement Rule

hcr.tex

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage{covington}
\usepackage{avm}
\begin{document}

%%begin novalidate
\begin{avm}
\avml
\[
    \textit{phrase} \\
    VAL & \[ COMPS \< \> \]
\]
$\rightarrow$ \hfil
\avmr
\textbf{H}
\[
    \textit{word} \\
    VAL &
    \[
        COMPS &
        \< \@1 , ... , \@n \>
    \]
\]
\@1 ... \@n
\avml
\avmr
\end{avm}\label{hcr}
%%end novalidate

\end{document}