actually belong to different object (official town names). First we add a variable indicating whether two pairs have the same official name:</p>
<div class="sourceCode" id="cb5"><pre class="sourceCode R"><code class="sourceCode r"><span id="cb5-1"><a href="#cb5-1" aria-hidden="true"></a><span class="op">&gt;</span><span class="st"> </span><span class="kw">compare_vars</span>(pairs, <span class="st">&quot;true&quot;</span>, <span class="dt">on_x =</span> <span class="st">&quot;official_name&quot;</span>,</sp