an><span class="va">states</span><span class="op">$</span><span class="va">mean</span><span class="op">$</span><span class="va">prior</span><span class="op">$</span><span class="va">t</span></span>
<span><span class="va">x.mean</span> <span class="op">=</span> <span class="va">fit</span><span class="op">$</span><span class="va">states</span><span class="op">$</span><span class="va">mean</span><span class="op">$</span><span class="va">prior</span><span class="op">$</span><span class="va">x</span></span>
<spa