Use of <var> in the section about BGPs

Co-authored-by: Ted Thibodeau Jr <[email protected]>

Author: hartig

spec/index.html

@@ -8944,9 +8944,9 @@ <h3>Basic Graph Patterns</h3>
           unordered collection of elements in which each element may appear more than once. It is
           described by a set of elements and a function giving the multiplicity of each of these
           elements (i.e., the number of times the element is contained in the multiset).</p>
-        <p>Write μ for solution mappings.</p>
-        <p>Write μ<sub>0</sub> for the mapping such that dom(μ<sub>0</sub>) is the empty set.</p>
-        <p>Write Ω<sub>0</sub> for the multiset consisting of exactly the empty mapping
+        <p>Write <var>μ</var> for solution mappings.</p>
+        <p>Write <var>μ<sub>0</sub></var> for the mapping such that <var>dom</var>(<var>μ<sub>0</sub></var>) is the empty set.</p>
+        <p>Write <var>Ω<sub>0</sub></var> for the multiset consisting of exactly the empty mapping
           μ<sub>0,</sub> with multiplicity 1. This is the join identity.</p>
         <p>Write μ(x) for the solution mapping variable x to RDF term t : { (x, t) }</p>
         <p>Write Ω(x) for the multiset consisting of exactly μ(?x-&gt;t), that is, { { (x, t) } }