Revert "a element for #555"

This reverts commit b98b0b2.

will resubmit as PR

Author: davidcarlisle

src/fundamentals.html

@@ -598,7 +598,7 @@ <h4 id="fund_globatt">Attributes Shared by all MathML Elements</h4>
 
      <tr>
       <td colspan="2" class="attdesc">
-	Can be used to establish the element as a hyperlink to the specified <em>URI</em>. Note that this is not supported on all elements in MathML Core, but is supported on the <a href="#presm_mrow"><code class="element">a</code></a> element. 
+	Can be used to establish the element as a hyperlink to the specified <em>URI</em>.
       </td>
      </tr>
     </tbody>

src/presentation-markup.html

@@ -3587,15 +3587,12 @@ <h3 id="presm_genlayout">General Layout Schemata</h3>
 
   <section>
    <h4 id="presm_mrow">Horizontally Group Sub-Expressions
-     <a class="coreyes" href="https://w3c.github.io/mathml-core/spec.html#dfn-mrow"><code class="defn starttag">&lt;mrow&gt;</code></a>,
-     <a class="coreyes" href="https://w3c.github.io/mathml-core/spec.html#dfn-a"><code class="defn starttag">&lt;a&gt;</code></a>
-   </h4>
+ <a class="coreyes" href="https://w3c.github.io/mathml-core/spec.html#dfn-mrow"><code class="defn starttag">&lt;mrow&gt;</code></a></h4>
 
  <section>
  <h5 id="presm_genlayout_desc">Description</h5>
 
- <p>An <code class="element">mrow</code> or <code class="element">a</code>
-   element is used to group together any
+ <p>An <code class="element">mrow</code> element is used to group together any
  number of sub-expressions, usually consisting of one or more <code class="element">mo</code> elements acting as <q>operators</q> on one
  or more other expressions that are their <q>operands</q>.</p>
 
@@ -3628,12 +3625,6 @@ <h5 id="presm_genlayout_desc">Description</h5>
  although the control of linebreaking is effected through attributes
  on other elements (see <a href="#presm_linebreaking"></a>).
  </p>
-
- <p>In MathML 4 <code class="element">mrow</code> and
- <code class="element">a</code> have identical behavior, however
- <code class="element">a</code>has been added for compatibility with MathML
- Core. MathML Core only supprts the <code class="attname">href</code>
- attribute on the <code class="element">a</code> element.</p>
 
  </section>