diff -r bcc9cbed10b1 -r 80ef03e39058 src/Modal/S4.thy
--- a/src/Modal/S4.thy	Thu Oct 10 11:09:03 1996 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,31 +0,0 @@
-(*  Title:      91/Modal/S4
-    ID:         $Id$
-    Author:     Martin Coen
-    Copyright   1991  University of Cambridge
-*)
-
-S4 = Modal0 +
-rules
-(* Definition of the star operation using a set of Horn clauses *)
-(* For system S4:  gamma * == {[]P | []P : gamma}               *)
-(*                 delta * == {<>P | <>P : delta}               *)
-
-  lstar0         "|L>"
-  lstar1         "$G |L> $H ==> []P, $G |L> []P, $H"
-  lstar2         "$G |L> $H ==>   P, $G |L>      $H"
-  rstar0         "|R>"
-  rstar1         "$G |R> $H ==> <>P, $G |R> <>P, $H"
-  rstar2         "$G |R> $H ==>   P, $G |R>      $H"
-
-(* Rules for [] and <> *)
-
-  boxR
-   "[| $E |L> $E';  $F |R> $F';  $G |R> $G';  
-           $E'         |- $F', P, $G'|] ==> $E          |- $F, []P, $G"
-  boxL     "$E,P,$F,[]P |-         $G    ==> $E, []P, $F |-          $G"
-
-  diaR     "$E          |- $F,P,$G,<>P   ==> $E          |- $F, <>P, $G"
-  diaL
-   "[| $E |L> $E';  $F |L> $F';  $G |R> $G';  
-           $E', P, $F' |-         $G'|] ==> $E, <>P, $F |- $G"
-end