diff --git a/docs/pyerrors/obs.html b/docs/pyerrors/obs.html
index fd75cbc8..d65897e6 100644
--- a/docs/pyerrors/obs.html
+++ b/docs/pyerrors/obs.html
@@ -1605,7 +1605,7 @@
 </span><span id="L-1401"><a href="#L-1401"><span class="linenos">1401</span></a><span class="sd">    &quot;&quot;&quot;</span>
 </span><span id="L-1402"><a href="#L-1402"><span class="linenos">1402</span></a>
 </span><span id="L-1403"><a href="#L-1403"><span class="linenos">1403</span></a>    <span class="k">if</span> <span class="nb">sorted</span><span class="p">(</span><span class="n">obs_a</span><span class="o">.</span><span class="n">names</span><span class="p">)</span> <span class="o">!=</span> <span class="nb">sorted</span><span class="p">(</span><span class="n">obs_b</span><span class="o">.</span><span class="n">names</span><span class="p">):</span>
-</span><span id="L-1404"><a href="#L-1404"><span class="linenos">1404</span></a>        <span class="k">raise</span> <span class="ne">Exception</span><span class="p">(</span><span class="s1">&#39;Ensembles do not fit&#39;</span><span class="p">)</span>
+</span><span id="L-1404"><a href="#L-1404"><span class="linenos">1404</span></a>        <span class="k">raise</span> <span class="ne">Exception</span><span class="p">(</span><span class="sa">f</span><span class="s2">&quot;Ensembles do not fit </span><span class="si">{</span><span class="nb">set</span><span class="p">(</span><span class="nb">sorted</span><span class="p">(</span><span class="n">obs_a</span><span class="o">.</span><span class="n">names</span><span class="p">))</span> <span class="o">^</span> <span class="nb">set</span><span class="p">(</span><span class="nb">sorted</span><span class="p">(</span><span class="n">obs_b</span><span class="o">.</span><span class="n">names</span><span class="p">))</span><span class="si">}</span><span class="s2">&quot;</span><span class="p">)</span>
 </span><span id="L-1405"><a href="#L-1405"><span class="linenos">1405</span></a>    <span class="k">if</span> <span class="nb">len</span><span class="p">(</span><span class="n">obs_a</span><span class="o">.</span><span class="n">cov_names</span><span class="p">)</span> <span class="ow">or</span> <span class="nb">len</span><span class="p">(</span><span class="n">obs_b</span><span class="o">.</span><span class="n">cov_names</span><span class="p">):</span>
 </span><span id="L-1406"><a href="#L-1406"><span class="linenos">1406</span></a>        <span class="k">raise</span> <span class="ne">Exception</span><span class="p">(</span><span class="s1">&#39;Error: Not possible to correlate Obs that contain covobs!&#39;</span><span class="p">)</span>
 </span><span id="L-1407"><a href="#L-1407"><span class="linenos">1407</span></a>    <span class="k">for</span> <span class="n">name</span> <span class="ow">in</span> <span class="n">obs_a</span><span class="o">.</span><span class="n">names</span><span class="p">:</span>
@@ -4517,7 +4517,7 @@ on the configurations in obs[i].idl. Default False.</li>
 </span><span id="correlate-1402"><a href="#correlate-1402"><span class="linenos">1402</span></a><span class="sd">    &quot;&quot;&quot;</span>
 </span><span id="correlate-1403"><a href="#correlate-1403"><span class="linenos">1403</span></a>
 </span><span id="correlate-1404"><a href="#correlate-1404"><span class="linenos">1404</span></a>    <span class="k">if</span> <span class="nb">sorted</span><span class="p">(</span><span class="n">obs_a</span><span class="o">.</span><span class="n">names</span><span class="p">)</span> <span class="o">!=</span> <span class="nb">sorted</span><span class="p">(</span><span class="n">obs_b</span><span class="o">.</span><span class="n">names</span><span class="p">):</span>
-</span><span id="correlate-1405"><a href="#correlate-1405"><span class="linenos">1405</span></a>        <span class="k">raise</span> <span class="ne">Exception</span><span class="p">(</span><span class="s1">&#39;Ensembles do not fit&#39;</span><span class="p">)</span>
+</span><span id="correlate-1405"><a href="#correlate-1405"><span class="linenos">1405</span></a>        <span class="k">raise</span> <span class="ne">Exception</span><span class="p">(</span><span class="sa">f</span><span class="s2">&quot;Ensembles do not fit </span><span class="si">{</span><span class="nb">set</span><span class="p">(</span><span class="nb">sorted</span><span class="p">(</span><span class="n">obs_a</span><span class="o">.</span><span class="n">names</span><span class="p">))</span> <span class="o">^</span> <span class="nb">set</span><span class="p">(</span><span class="nb">sorted</span><span class="p">(</span><span class="n">obs_b</span><span class="o">.</span><span class="n">names</span><span class="p">))</span><span class="si">}</span><span class="s2">&quot;</span><span class="p">)</span>
 </span><span id="correlate-1406"><a href="#correlate-1406"><span class="linenos">1406</span></a>    <span class="k">if</span> <span class="nb">len</span><span class="p">(</span><span class="n">obs_a</span><span class="o">.</span><span class="n">cov_names</span><span class="p">)</span> <span class="ow">or</span> <span class="nb">len</span><span class="p">(</span><span class="n">obs_b</span><span class="o">.</span><span class="n">cov_names</span><span class="p">):</span>
 </span><span id="correlate-1407"><a href="#correlate-1407"><span class="linenos">1407</span></a>        <span class="k">raise</span> <span class="ne">Exception</span><span class="p">(</span><span class="s1">&#39;Error: Not possible to correlate Obs that contain covobs!&#39;</span><span class="p">)</span>
 </span><span id="correlate-1408"><a href="#correlate-1408"><span class="linenos">1408</span></a>    <span class="k">for</span> <span class="n">name</span> <span class="ow">in</span> <span class="n">obs_a</span><span class="o">.</span><span class="n">names</span><span class="p">:</span>