\section{Overview - TODO - OPEN Questions for Release 3.3}

\subsection{Overview}
{\em this section is for the reviewer and to be removed for the release. }

We introduced four traits classes and related concepts, for more details see 
section \ref{caf_ref::classified_refernce_pages}
\begin{itemize}
\item \ccc{Algebraic_structure_traits} reflects the algebraic concepts of a 
      type. e.g. \ccc{Field}, \ccc{EuclideanRing}
\item \ccc{Real_embeddable_traits} is use for number types that are embedded on 
      the real axis. 
\item \ccc{Coercion_traits}, reflects interoperability of types. 
\item \ccc{Fraction_traits}, more general than \ccc{Rational_traits}.
\end{itemize}

Number types, polynomials and linear algebra are not part of this package. 

\subsection{Changes}
\begin{itemize}
\item added concept \ccc{FromDoubleConstructible}
\item \ccc{FromSmallIntConstructible} -> \ccc{FromIntConstructible}
\item rm IsFinite from \ccc{RealEmbeddable} concept
      function \ccc{CGAL::is_finite} for float, double, long double 
\item Moved Max/Min/Is\_valid/Boolean\_tag.. to STL-extension 
\item mv \ccc{AdaptableUnaryFunction} and \ccc{AdaptableBinaryFunction} 
      to STL-extension
\item \ccc{Coercion_traits} replaces \ccc{Binary_operator_result}
\item \ccc{Algebraic_structure_traits} replaces \ccc{Number_type_traits} 
\item \ccc{Fraction_traits} should be used instead of \ccc{Rational_traits}\\
      \ccc{Rational_traits} is kept for backward compatibility.
\item gcd(0,0)=0, in particular gcd(x,0) is allowed now and is the unit normal 
      of x. For more details see \ccc{AlgebraicStructureTraits::Gcd}. \\
\end{itemize}

TODO:
\begin{itemize} 
\item add a new entry in the globally maintained Bib file.
\end{itemize}

Keep in mind: 
\begin{itemize} 
\item Should we add Ipower? motivation see introduction of Square. 
\item generic interoperable operators via Coercion Traits
\item may add arithmetic functors as Add, Sub to Algebraic Structure Traits
\item may add more fundamental concepts, such as Abelian Group.
\item The second operator of \ccc{AlgebraicStructureTraits::RootOf} is not 
        part of the concept, since the difference in the interface of the 
        according function provided by the two possible models \ccc{leda::real}
        and \ccc{CORE::Expr} is to large.  
\item can we do better for \ccc{mpz_class}, \ccc{mpq_class }
\item ToDoubleInterval etc. 
\item what about namespace of leda types ? 
     \ccc{leda_integer} vs. \ccc{leda::integer}
\item We had a quick look at \ccc{Nef_polynomial}. \\ 
      is it \ccc{RealEmbeddable}?
\end{itemize}

