PLFA agda exercises
<article class="post">
    $^$${ next() }
    <header class="post-header" aria-label="Chapter">
        <h1 class="post-title" $if(anchor)$id="$anchor$"$endif$>$title$</h1>
    </header>
    <div class="post-content">
$body$
    </div>
    $^$${ next() }
</article>