Put captured RDF Dataset text in a box

Author: afs

spec/index.html

@@ -7878,11 +7878,13 @@ <h2>Definition of SPARQL</h2>
         <h3>Initial Definitions</h3>
         <section id="sparqlDataset">
           <h4>RDF Dataset</h4>
-          <div>
-            <p>The concept of an <a data-cite="RDF12-CONCEPTS#dfn-rdf-dataset">RDF Dataset</a> is defined in [[RDF12-CONCEPTS]].</p>
-            <p>For the following definitions, we capture each RDF dataset as a set:<br>
-              { G, (&lt;u<sub>1</sub>&gt;, G<sub>1</sub>), (&lt;u<sub>2</sub>&gt;, G<sub>2</sub>),
-              ... (&lt;u<sub>n</sub>&gt;, G<sub>n</sub>) }<br>
+          <p>The concept of an <a data-cite="RDF12-CONCEPTS#dfn-rdf-dataset">RDF Dataset</a> is defined in [[RDF12-CONCEPTS]].</p>
+          <p>For the following definitions, we capture each RDF dataset as a set:</p>
+          <div class="defn">
+            <p>
+            { G, (&lt;u<sub>1</sub>&gt;, G<sub>1</sub>), (&lt;u<sub>2</sub>&gt;, G<sub>2</sub>),
+              ... (&lt;u<sub>n</sub>&gt;, G<sub>n</sub>) }
+            
               where G and each G<sub>i</sub> are graphs, and each &lt;u<sub>i</sub>&gt; is an IRI or blank node. Each
               &lt;u<sub>i</sub>&gt; is distinct.</p>
             <p>G is called the default graph. (&lt;u<sub>i</sub>&gt;, G<sub>i</sub>) are called named