doc-src/Ref/classical.tex

 \begin{ttbox}
 Delrules : thm list -> unit
 \end{ttbox}
 deletes rules from the current claset. 
 
-\medskip A few further functions are available as uppercase versions only:
-\begin{ttbox}
-AddXIs, AddXEs, AddXDs: thm list -> unit
-\end{ttbox}
-\indexbold{*AddXIs} \indexbold{*AddXEs} \indexbold{*AddXDs} augment the
-current claset by \emph{extra} introduction, elimination, or destruct rules.
-These provide additional hints for the basic non-automated proof methods of
-Isabelle/Isar \cite{isabelle-isar-ref}.  The corresponding Isar attributes are
-``$intro?$'', ``$elim?$'', and ``$dest?$''.  Note that these extra rules do
-not have any effect on classic Isabelle tactics.
-
 
 \subsection{Accessing the current claset}
 \label{sec:access-current-claset}
 
 the functions to access the current claset are analogous to the functions