n>
<span>  <span class="va">dx</span> <span class="op">~</span> <span class="va">theta</span> <span class="op">*</span> <span class="op">(</span><span class="va">mu</span><span class="op">-</span><span class="va">x</span><span class="op">+</span><span class="va">u</span><span class="op">)</span> <span class="op">*</span> <span class="va">dt</span> <span class="op">+</span> <span class="va">sigma_x</span><span class="op">*</span><span class="va">dw</span></span>
<span><span class="op">)</span></span>
<span><