update page

Author: nadia-polikarpova

docs/lectures/07-classes.html

@@ -927,10 +927,6 @@ <h2 id="type-classes-outline-3">Type Classes: Outline</h2>
 <br>
 <br>
 <br></p>
-<h2 id="using-typeclasses">Using Typeclasses</h2>
-<p>Now let’s see how to write code that uses type classes!</p>
-<p><br>
-<br></p>
 <p>Let’s build a small library for dictionaries mapping keys <code class="sourceCode haskell">k</code> to values <code class="sourceCode haskell">v</code></p>
 <div class="sourceCode" id="cb31"><pre class="sourceCode haskell"><code class="sourceCode haskell"><span id="cb31-1"><a href="#cb31-1" aria-hidden="true" tabindex="-1"></a><span class="kw">data</span> <span class="dt">Dict</span> k v</span>
 <span id="cb31-2"><a href="#cb31-2" aria-hidden="true" tabindex="-1"></a>  <span class="ot">=</span> <span class="dt">Empty</span>                <span class="co">-- empty dictionary</span></span>

lectures/07-classes.md

@@ -955,13 +955,6 @@ True
 <br>
 <br>
 
-## Using Typeclasses
-
-Now let's see how to write code that uses type classes!
-
-<br>
-<br>
-
 Let's build a small library for dictionaries mapping keys `k` to values `v`
 
 ```haskell