 joint distributions, we can assign a
transition probability function.</p>
<div class="highlight-ipython notranslate"><div class="highlight"><pre><span></span><span class="gp">In [6]: </span><span class="k">def</span> <span class="nf">identity_transition</span><span class="p">(</span><span class="n">x</span><span class="p">,</span><span class="n">y</span><span class="p">):</span>
<span class="gp">   ...: </span>    <span class="k">if</span> <span class="n">x</span><span class="o">==</span><span class="n">y<