Fix formatting of 'micro'

chapters/unitexpressions.tex

@@ -69,7 +69,7 @@ \section{The Syntax of Unit Expressions}\label{the-syntax-of-unit-expressions}
 A \lstinline[language=grammar]!unit-operand! should first be interpreted as a \lstinline[language=grammar]!unit-symbol! and only if not successful the second alternative assuming a prefixed operand should be exploited.
 There must be no spacing between the \lstinline[language=grammar]!unit-symbol! and a possible \lstinline[language=grammar]!unit-prefix!.
 The values of the prefixes are according to the ISO standard.
-The letter \lstinline!u! is used as a symbol for the prefix micro.
+The letter \lstinline!u! is used as a symbol for the prefix \emph{micro}.
 
 \begin{nonnormative}
 A tool may present \lstinline!Ohm! as $\Omega$ and the prefix \lstinline!u! as $\mu$, and similarly \lstinline!m2! as m\textsuperscript{2}.