>)</span> <span class="op">|&gt;</span> </span>
<span> <span class="fu"><a href="reference/add_variable.html">add_variable</a></span><span class="op">(</span><span class="st">"W"</span>, init <span class="op">=</span> <span class="fl">1</span>, desc <span class="op">=</span> <span class="st">"Wage rate"</span><span class="op">)</span></span>
<span></span>
<span><span class="va">model_sim</span><span class="op">$</span><span class="va">variables</span></span>
<span></span>
<span><span class="co">## # A tibbl