+++ /dev/null
-\section{Introduction}
-
-This paper presents {\MathQL} version 4 which is the latest version of the
-language, fully developed by the Author.
-For a description of the previous versions of {\MathQL} see: \cite{Gui03}
-(version 3), \cite{GS03} (version 2), \cite{Lor02} (version 1).
-The main novelties of this version are the elimination of some cast operators
-(producing a substantial simplification in the query structure and semantics),
-a clear distinction between the core language and the auxiliary functions of
-the basic library, a support for query generating functions, the possibility
-of extending the language adding new libraries of functions and a more uniform
-textual syntax.
-{\MathQL}.4 incorporates the features of {\MathQL}.3 not documented on paper%
-\footnote
-{See the ``what's new'' section of {\MathQL} Web Site:
-\CURI{helm.cs.unibo.it/mathql}.}
-and adds some new features improving {\MathQL} capabilities to post-process
-the query results.
-
-\input{mathql_introduction_avsets}
-\input{mathql_introduction_property}
-\input{mathql_introduction_core}
-\input{mathql_introduction_basic}
-\input{mathql_introduction_textual}