Don't emphasise "or" in Sigma-Algebra definition

background.tex

@@ -66,7 +66,7 @@
   \item[\(1 + A \times X\)] are lists,
   \item[\(A + X^2\)] are binary trees,
   \item[\(\prod_{\sigma \in \Sigma} X^{\ar{\sigma}}\)],
-    \emph{Term- or \(\Sigma\)-algebra}, over a set of operations \(\Sigma\) and an
+    \emph{Term-} or \emph{\(\Sigma\)-algebra}, over a set of operations \(\Sigma\) and an
     arity function \(\ar : \map{\Sigma}{\mathbb{N}}\).
   \end{description}