Improve typesetting in the digraph example

background.tex

@@ -118,8 +118,9 @@
   \href{https://en.wikipedia.org/wiki/Strongly_connected_component}{strongly
     connected components}, i.e.\
   \[ \forall a, b \in V(X) \st a \sim_{E(\mathfrak{A})} b \implies f(a)
-    \sim_{E(\mathfrak{B})} f(b),\] where \(x \sim_{E{\mathfrak{G}}} y\) says that
-  there is a path from \(x\) to \(y\) in the digraph \(\mathfrak{G}\).
+    \sim_{E(\mathfrak{B})} f(b),\] where \(x \sim_{E(\mathfrak{G})} y\) says that
+  there is a path from \(x\) to \(y\) in the digraph \(\mathfrak{G}\),
+  over the transitive-reflexive closure of edges.
 
   The \defn{initial}{initial object} are therefore the empty graph
   \(V = \{\}\), since there are no components to be preserved, and the