Missing space (#1029)

Author: siwelwerd

source/linear-algebra/source/04-MX/01.ptx

@@ -394,7 +394,7 @@ in terms of matrix multiplication.</p>
             </figure>
 
 <ul>
-<li>An <em>adjacency matrix</em> for this map is a matrix that has the number of roads from city <m>i</m> to city <m>j</m> in the <m>(i,j)</m> entry of the matrix. A road is a path of length exactly 1. All <m>(i,i)</m>entries are 0. Write the adjacency matrix for this map, with the cities in alphabetical order.</li>
+<li>An <em>adjacency matrix</em> for this map is a matrix that has the number of roads from city <m>i</m> to city <m>j</m> in the <m>(i,j)</m> entry of the matrix. A road is a path of length exactly 1. All <m>(i,i)</m> entries are 0. Write the adjacency matrix for this map, with the cities in alphabetical order.</li>
 
 <li>What does the square of this matrix tell you about the map? The cube? The <m>n</m>-th power?</li>
 </ul>