fix typo; closes #415

Author: rzach

content/incompleteness/introduction/definitions.tex

@@ -79,8 +79,8 @@
 \end{defn}
 
 $\Th{TA}$ is a theory, for whenever $\Th{TA} \Entails !A$, $!A$ is
-satisfied in every !!{structure} which satisfies $\Th{TA}$. Since
-$\Sat{M}{\Th{TA}}$, $\Sat{M}{!A}$, and so $!A \in \Th{TA}$.
+satisfied in every !!{structure} which satisfies~$\Th{TA}$. Since
+$\Sat{N}{\Th{TA}}$, we have that~$\Sat{N}{!A}$, and so $!A \in \Th{TA}$.
 
 The other way to specify a theory~$\Gamma$ is as the set of
 !!{sentence}s entailed by some set of sentences~$\Gamma_0$. In that