diff --git a/docs/pyerrors/linalg.html b/docs/pyerrors/linalg.html
index b7ec79d4..50eccee2 100644
--- a/docs/pyerrors/linalg.html
+++ b/docs/pyerrors/linalg.html
@@ -331,7 +331,7 @@
 </span><span id="L-232"><a href="#L-232"><span class="linenos">232</span></a><span class="k">def</span> <span class="nf">_mat_mat_op</span><span class="p">(</span><span class="n">op</span><span class="p">,</span> <span class="n">obs</span><span class="p">,</span> <span class="o">**</span><span class="n">kwargs</span><span class="p">):</span>
 </span><span id="L-233"><a href="#L-233"><span class="linenos">233</span></a>    <span class="sd">&quot;&quot;&quot;Computes the matrix to matrix operation op to a given matrix of Obs.&quot;&quot;&quot;</span>
 </span><span id="L-234"><a href="#L-234"><span class="linenos">234</span></a>    <span class="c1"># Use real representation to calculate matrix operations for complex matrices</span>
-</span><span id="L-235"><a href="#L-235"><span class="linenos">235</span></a>    <span class="k">if</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">obs</span><span class="o">.</span><span class="n">ravel</span><span class="p">()[</span><span class="mi">0</span><span class="p">],</span> <span class="n">CObs</span><span class="p">):</span>
+</span><span id="L-235"><a href="#L-235"><span class="linenos">235</span></a>    <span class="k">if</span> <span class="nb">any</span><span class="p">(</span><span class="nb">isinstance</span><span class="p">(</span><span class="n">o</span><span class="p">,</span> <span class="n">CObs</span><span class="p">)</span>  <span class="k">for</span> <span class="n">o</span> <span class="ow">in</span> <span class="n">obs</span><span class="o">.</span><span class="n">ravel</span><span class="p">()):</span>
 </span><span id="L-236"><a href="#L-236"><span class="linenos">236</span></a>        <span class="n">A</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">empty_like</span><span class="p">(</span><span class="n">obs</span><span class="p">)</span>
 </span><span id="L-237"><a href="#L-237"><span class="linenos">237</span></a>        <span class="n">B</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">empty_like</span><span class="p">(</span><span class="n">obs</span><span class="p">)</span>
 </span><span id="L-238"><a href="#L-238"><span class="linenos">238</span></a>        <span class="k">for</span> <span class="p">(</span><span class="n">n</span><span class="p">,</span> <span class="n">m</span><span class="p">),</span> <span class="n">entry</span> <span class="ow">in</span> <span class="n">np</span><span class="o">.</span><span class="n">ndenumerate</span><span class="p">(</span><span class="n">obs</span><span class="p">):</span>