first edition: some fixes2

Author: kariminf

book/classObject.tex

@@ -445,7 +445,7 @@ \subsection{Python}
 
 \subsection{Ruby}
 
-Static fields are defined inside the class block using \keyword[Ruby]{\@\@}, while dynamic fields are defined inside the constructor or the class block using the keyword \keyword[Ruby]{\@}. 
+Static fields are defined inside the class block using \keyword[Ruby]{@@}, while dynamic fields are defined inside the constructor or the class block using the keyword \keyword[Ruby]{@}. 
 
 \lstinputlisting[language={[KB]Ruby}, linerange={3-9,11-11,25-25}, style=codeStyle]{../codes/ruby/clsobj/person.rb}
 

book/oop4coders.tex

@@ -15,7 +15,7 @@
 \cover{../img/cover.jpg}
 \license{../img/cc-by-sa.png}
 
-%\setplainversion
+\setplainversion
 
 \begin{document}
 
@@ -65,6 +65,7 @@
 \addcontentsline{toc}{chapter}{Index}
 
 \cleardoublepage
+\pagestyle{empty}
 \vspace*{\fill}
 \Huge\color{indigo}
 \begin{center}