code>xa</code></th><td><p>An <code>x</code> value</p></td></tr><tr><th style="width:25%;"><code>ya</code></th><td><p>A <code>y</code> value</p></td></tr></table></div></div><div class="field "><a name="subtract"></a><h3 class="anchor"><code><span class="label label-meta label-meta-value" title="Used to store default values for fields and function arguments.">@:value({ result : null })</span><a href="#subtract"><span class="identifier">subtract</span></a>(<span style="white-space:nowrap">v:<a class="type" ti