diff --git a/README.md b/README.md
index e3c16f2..fec5ad2 100644
--- a/README.md
+++ b/README.md
@@ -373,7 +373,7 @@ import re
 
 ### Special Sequences
 * **By default digits, whitespaces and alphanumerics from all alphabets are matched, unless `'flags=re.ASCII'` argument is used.**
-* **Use capital letters for negation.**
+* **Use capital letter for negation.**
 ```python
 '\d' == '[0-9]'                                # Digit
 '\s' == '[ \t\n\r\f\v]'                        # Whitespace
@@ -652,10 +652,10 @@ from dateutil.tz import UTC, tzlocal, gettz
 
 ### Arithmetics
 ```python
-<TD>     = <D/DT> -  <D/DT>
-<D/DT>   = <D/DT> ±  <TD>
-<TD>     = <TD>   ±  <TD>
-<TD>     = <TD>   */ <real>
+<TD>     = <D/DT> - <D/DT>
+<D/DT>   = <D/DT> ± <TD>
+<TD>     = <TD>   ± <TD>
+<TD>     = <TD>   * <real>
 ```
 
 
diff --git a/index.html b/index.html
index 3c1c7e8..bf34912 100644
--- a/index.html
+++ b/index.html
@@ -476,7 +476,7 @@ to_exclusive   = &lt;range&gt;.stop
 
 <div><h3 id="specialsequences">Special Sequences</h3><ul>
 <li><strong>By default digits, whitespaces and alphanumerics from all alphabets are matched, unless <code class="python hljs"><span class="hljs-string">'flags=re.ASCII'</span></code> argument is used.</strong></li>
-<li><strong>Use capital letters for negation.</strong></li>
+<li><strong>Use capital letter for negation.</strong></li>
 </ul><pre><code class="python language-python hljs"><span class="hljs-string">'\d'</span> == <span class="hljs-string">'[0-9]'</span>                                <span class="hljs-comment"># Digit</span>
 <span class="hljs-string">'\s'</span> == <span class="hljs-string">'[ \t\n\r\f\v]'</span>                        <span class="hljs-comment"># Whitespace</span>
 <span class="hljs-string">'\w'</span> == <span class="hljs-string">'[a-zA-Z0-9_]'</span>                         <span class="hljs-comment"># Alphanumeric</span>
@@ -696,10 +696,10 @@ shuffle(&lt;list&gt;)
 <li><strong>When parsing, <code class="python hljs"><span class="hljs-string">'%z'</span></code> also accepts <code class="python hljs"><span class="hljs-string">'±HH:MM'</span></code>.</strong></li>
 <li><strong>For abbreviated weekday and month use <code class="python hljs"><span class="hljs-string">'%a'</span></code> and <code class="python hljs"><span class="hljs-string">'%b'</span></code>.</strong></li>
 </ul>
-<div><h3 id="arithmetics">Arithmetics</h3><pre><code class="python language-python apache hljs">&lt;TD&gt;     = &lt;D/DT&gt; -  &lt;D/DT&gt;
-&lt;D/DT&gt;   = &lt;D/DT&gt; ±  &lt;TD&gt;
-&lt;TD&gt;     = &lt;TD&gt;   ±  &lt;TD&gt;
-&lt;TD&gt;     = &lt;TD&gt;   */ &lt;real&gt;
+<div><h3 id="arithmetics">Arithmetics</h3><pre><code class="python language-python apache hljs">&lt;TD&gt;     = &lt;D/DT&gt; - &lt;D/DT&gt;
+&lt;D/DT&gt;   = &lt;D/DT&gt; ± &lt;TD&gt;
+&lt;TD&gt;     = &lt;TD&gt;   ± &lt;TD&gt;
+&lt;TD&gt;     = &lt;TD&gt;   * &lt;real&gt;
 </code></pre></div>
 
 <div><h2 id="arguments"><a href="#arguments" name="arguments">#</a>Arguments</h2><div><h3 id="insidefunctioncall">Inside Function Call</h3><pre><code class="python language-python hljs">&lt;function&gt;(&lt;positional_args&gt;)                  <span class="hljs-comment"># f(0, 0)</span>