The test should be written to check if there is no emphasis mark or ruby character inside the composition. To make this easy to observe, we need a glyph where:
<ul>
<li>it does not overlap ruby text, emphasis mark, or any decoration
</ul>
<p>The following is an idea for such glyph: it draws overline and underline but does not do so in between them.
<figure>
<img src="img/over_and_under.svg" width="300">
</figure>
<p>With such glyph, the test would be written as:
<figure>
<pre class="highlight"><code>&lt;sty