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+++ b/Cut/CL-plugin.html Thu Mar 15 15:50:18 2012 +0000
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+<HTML lang=en>
+<HEAD>
+<TITLE> Christian Urban </TITLE>
+<BASE HREF="http://www4.in.tum.de/~urbanc/Cut/">
+</HEAD>
+
+<BODY TEXT="#000000"
+ BGCOLOR="#000080"
+ LINK="#0000EF"
+ VLINK="#51188E"
+ ALINK="#FF0000">
+
+<TABLE WIDTH="100%"
+ COLS="2"
+ BGCOLOR="#000080"
+ BORDER="0"
+ FRAME="none"
+ CELLPADDING="10"
+ CELLSPACING="2"
+ RULES="COLS,ROWS">
+
+<!-- left column -->
+<TR>
+<TD BGCOLOR="#FFFFFF"
+ WIDTH="24%"
+ VALIGN="TOP"
+ ROWSPAN="4">
+
+<B>Links</B><BR>
+<A HREF="http://www4.in.tum.de/~urbanc/cutapplet.html">Home</A><BR>
+<A HREF="http://www4.in.tum.de/~urbanc/Cut/index.html">Applet Home</A><BR><BR><p>
+
+<B>Java Versions</B><BR>
+<A HREF="http://www4.in.tum.de/~urbanc/Cut/CL.html">CL</A><BR>
+<A HREF="http://www4.in.tum.de/~urbanc/Cut/LJT.html">LJT</A><BR>
+<A HREF="http://www4.in.tum.de/~urbanc/Cut/ND.html">ND</A><BR><BR>
+
+<B>Plugin Versions</B><BR>
+<A HREF="http://www4.in.tum.de/~urbanc/Cut/CL-plugin.html">CL</A><BR>
+<A HREF="http://www4.in.tum.de/~urbanc/Cut/LJT-plugin.html">LJT</A><BR>
+<A HREF="http://www4.in.tum.de/~urbanc/Cut/ND-plugin.html">ND</A><BR>
+
+<BR>
+<BR>
+
+<A HREF="http://isabelle.in.tum.de/nominal/">
+<IMG SRC="ribbon.gif" ALT="" style="width: 114px; height: 100px;" align="left">
+</A>
+</TD>
+
+
+<!-- right column -->
+<TD BGCOLOR="#FFFFFF" WIDTH="75%">
+<A NAME="Home"></A>
+<H2>Cut-Elimination in Classical Logic</H2>
+
+If you use this applet it is strongly(!) recommended to have read the the paper on
+strong normalisation of cut-elimination in classical logic by Urban and Bierman
+[<A HREF="http://www4.in.tum.de/~urbanc/Publications/fi-01.ps.gz">ps.gz</A>,
+ <A HREF="http://www4.in.tum.de/~urbanc/Publications/fi-01.pdf">pdf</A>].
+Mayor difference between the standard sequent calculus and the sequent calculus
+implemented by the applet is that the rules contraction and weakening are completely
+implicit. This means that sequents consist of two sets of (labelled) formulae,
+as opposed to lists or multisets of formulae. Although this is very simple, it
+needs some time to get used to.
+</TD>
+</TR>
+
+<TR>
+<TD BGCOLOR="#FFFFFF" WIDTH="75%">
+<B>How to use it?</B>
+If your browser is playing game with Java, then you will see a window
+with a number of examples. When pressing on one of the buttons, a new
+window will pop up. What follows is a brief explanation of all
+the features available in this window.
+</TD>
+</TR>
+
+<TR>
+<TD BGCOLOR="#FFFFFF" WIDTH="75%">
+<B>Buttons and Keys</B>
+<UL>
+<LI> The buttons
+ <IMG SRC="http://www4.in.tum.de/~urbanc/Cut/l.jpg"> and
+ <IMG SRC="http://www4.in.tum.de/~urbanc/Cut/r.jpg"> are for
+ commuting cuts, which can slide up either in the right or left proof branch.
+<LI> Pressing on <IMG SRC="http://www4.in.tum.de/~urbanc/Cut/x.jpg">
+ , <IMG SRC="http://www4.in.tum.de/~urbanc/Cut/x1.jpg"> or
+ <IMG SRC="http://www4.in.tum.de/~urbanc/Cut/x2.jpg">
+ `fires' a logical cut. The latter two buttons correspond to the two possible
+ nestings of multiplicative logical cuts.
+<LI> If you use the <B>left mouse button</B> for pressing on those buttons,
+ then the new proof will appear inside the window. Whereas if you use
+ the <B>right mouse button</B>, a new window will pop up and
+ the new proof will be displayed in this window. Use the right mouse
+ button if you want to compare a proof and its reduct(s).
+<LI> The keys <B>Page-up</B> and <B>Page-down</B> zoom in or out of a proof
+ respectively.
+</UL>
+</TD>
+</TR>
+
+<TR>
+<TD BGCOLOR="#FFFFFF" WIDTH="75%">
+<B>Menu Functions</B>
+
+<UL>
+<LI> <B>Zoom in</B> and <B>Zoom out</B> work like Page-up and Page-down,
+ respectively.
+<LI> <B>Unicode</B> If this radiobutton is switched on, logic symbols
+ are displayed in unicode, otherwise in ascii. (This is for the
+ poor guys who have a browser and/or operating system which cannot handle
+ unicode.)
+<LI> <B>Labels</B> As mentioned earlier the sequents are composed of
+ two sets of labelled
+ formulae, not multisets of formulae as in the standard formulation
+ of sequent calculus. Enabling this radiobutton causes that labels are
+ drawn. Use this when you are unsure where implicit contractions are.
+<LI> <B>Auxiliary Substitution</B> If you have read the paper referred
+ above, you know what this does.
+<LI> <B>Gentzen's D.N.Transl.</B> and <B>Kolmogorov's D.N.Transl.</B>
+ perform double negation translations on the current proof.
+</UL>
+</TD>
+</TR>
+
+</TABLE>
+<center>
+<!--"CONVERTED_APPLET"-->
+<!-- HTML CONVERTER -->
+<OBJECT classid="clsid:CAFEEFAC-0013-0001-0000-ABCDEFFEDCBA"
+WIDTH = 1 HEIGHT = 1 codebase="http://java.sun.com/products/plugin/1.3.1/jinstall-131-win32.cab#Version=1,3,1,0">
+<PARAM NAME = CODE VALUE = "MyApplet.class" >
+<PARAM NAME = ARCHIVE VALUE = MyApplet.zip >
+
+<PARAM NAME="type" VALUE="application/x-java-applet;jpi-version=1.3.1">
+<PARAM NAME="scriptable" VALUE="false">
+<PARAM NAME = "calculi" VALUE ="A">
+<COMMENT>
+<EMBED type="application/x-java-applet;jpi-version=1.3.1" CODE = "MyApplet.class" ARCHIVE = MyApplet.zip WIDTH = 1 HEIGHT = 1 calculi = "A" scriptable=false pluginspage="http://java.sun.com/products/plugin/1.3.1/plugin-install.html"><NOEMBED>
+<p><blink><FONT COLOR="#800000">
+Applet should appear in a new window, but you don't have Java enabled in your browser.
+</FONT></blink><p>
+</NOEMBED>
+</EMBED>
+</COMMENT>
+</OBJECT>
+
+<!--
+<APPLET CODE = "MyApplet.class" ARCHIVE = MyApplet.zip WIDTH = 1 HEIGHT = 1>
+<PARAM NAME = "calculi" VALUE ="A">
+<p><blink><FONT COLOR="#800000">
+Applet should appear in a new window, but you don't have Java enabled in your browser.
+</FONT></blink><p>
+
+</APPLET>
+-->
+
+
+<!--"END_CONVERTED_APPLET"-->
+
+
+</center>
+<P><!-- Created: Tue Jul 3 21:01:42 BST 2001 -->
+<!-- hhmts start -->
+Last modified: Sat Mar 3 05:17:41 CET 2007
+<!-- hhmts end -->
+</BODY>
+</HTML>