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1 <HTML lang=en> |
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2 <HEAD> |
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3 <TITLE> Christian Urban </TITLE> |
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4 <BASE HREF="http://www4.in.tum.de/~urbanc/Cut/"> |
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5 </HEAD> |
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6 |
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7 <BODY TEXT="#000000" |
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20 RULES="COLS,ROWS"> |
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21 |
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22 <!-- left column --> |
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23 <TR> |
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24 <TD BGCOLOR="#FFFFFF" |
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25 WIDTH="24%" |
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26 VALIGN="TOP" |
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27 ROWSPAN="4"> |
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28 |
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29 <B>Links</B><BR> |
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30 <A HREF="http://www4.in.tum.de/~urbanc/index.html">Home</A><BR> |
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31 <A HREF="http://www4.in.tum.de/~urbanc/Cut/cutapplet.html">Applet Home</A><BR><BR><p> |
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32 |
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33 <B>Java Versions</B><BR> |
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34 <A HREF="http://www4.in.tum.de/~urbanc/Cut/CL.html">CL</A><BR> |
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35 <A HREF="http://www4.in.tum.de/~urbanc/Cut/LJT.html">LJT</A><BR> |
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36 <A HREF="http://www4.in.tum.de/~urbanc/Cut/ND.html">ND</A><BR><BR> |
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37 |
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38 <B>Plugin Versions</B><BR> |
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39 <A HREF="http://www4.in.tum.de/~urbanc/Cut/CL-plugin.html">CL</A><BR> |
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40 <A HREF="http://www4.in.tum.de/~urbanc/Cut/LJT-plugin.html">LJT</A><BR> |
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41 <A HREF="http://www4.in.tum.de/~urbanc/Cut/ND-plugin.html">ND</A><BR> |
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42 |
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43 <BR> |
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44 <BR> |
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45 |
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46 <A HREF="http://isabelle.in.tum.de/nominal/"> |
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47 <IMG SRC="ribbon.gif" ALT="" style="width: 114px; height: 100px;" align="left"> |
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48 </A> |
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49 </TD> |
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50 |
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51 |
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52 <!-- right column --> |
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53 <TD BGCOLOR="#FFFFFF" WIDTH="75%"> |
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54 <A NAME="Home"></A> |
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55 <H2>Cut-Elimination in Herbelin's calculus for intuitionistic logic</H2> |
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56 |
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57 Recommended reading for this applet is a paper by Dyckhoff and Urban, |
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58 [<A HREF="http://www-theory.dcs.st-and.ac.uk/~rd/publications/MJES/DyckhoffUrbanWestApp01.rev.ps">ps</A>, |
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59 <A HREF="http://www-theory.dcs.st-and.ac.uk/~rd/publications/MJES/DyckhoffUrbanWestApp01.rev.ps">pdf</A>]. |
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60 Mayor difference between the standard sequent calculus and Herbelin's sequent calculus |
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61 is that in the cut-free fragment "there are no semantically |
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62 trivial permutations of the inference rules, where by 'semantically trivial' we mean |
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63 'interpreted in NJ as true equations between to (normal) deductions'" |
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64 (from [<A HREF="http://www-theory.dcs.st-and.ac.uk/~rd/publications/SLPaper.corr.ps">ps</A>]). |
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65 </TD> |
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66 </TR> |
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67 |
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68 <TR> |
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69 <TD BGCOLOR="#FFFFFF" WIDTH="75%"> |
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70 <B>How to use it?</B> |
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71 If your browser is working correctly, then you will see a window |
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72 with two examples (more added if you suggest some). When pressing on |
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73 one of the buttons, a new window will pop up. What follows |
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74 is a brief explanation of all the features available in this window. |
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75 </TD> |
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76 </TR> |
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77 |
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78 <TR> |
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79 <TD BGCOLOR="#FFFFFF" WIDTH="75%"> |
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80 <B>Buttons and Keys</B> |
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81 <UL> |
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82 <LI> The buttons |
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83 <IMG SRC="http://www4.in.tum.de/~urbanc/Cut/x.jpg"> |
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84 `fire' cuts (not all cuts necessarily have such buttons). |
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85 <LI> If you use the <B>left mouse button</B> for pressing on those buttons, |
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86 then the new proof will appear inside the window. Whereas if you use |
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87 the <B>right mouse button</B>, a new window will pop up and |
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88 the new proof will be displayed in this window. Use the right mouse |
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89 button if you want to compare a proof and its reduct. |
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90 <LI> The keys <B>Page-up</B> and <B>Page-down</B> zoom in or out of a proof |
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91 respectively. |
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92 </UL> |
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93 </TD> |
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94 </TR> |
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95 |
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96 <TR> |
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97 <TD BGCOLOR="#FFFFFF" WIDTH="75%"> |
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98 <B>Menu Functions</B> |
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99 |
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100 <UL> |
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101 <LI> <B>Zoom in</B> and <B>Zoom out</B> work like Page-up and Page-down, |
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102 respectively. |
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103 <LI> <B>Unicode</B> If this radiobutton is switched on, logic symbols |
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104 are displayed in unicode, otherwise in ascii. (This is for the |
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105 poor guys who have a browser and/or operating system which cannot handle |
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106 unicode.) |
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107 <LI> <B>Labels</B> As mentioned earlier the sequents are composed of |
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108 two sets of labelled |
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109 formulae, not multisets of formulae as in the standard formulation |
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110 of sequent calculus. Enabling this radiobutton causes that labels are |
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111 drawn. Use this when you are unsure where implicit contractions are. |
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112 <LI> <B>Compact printing</B> In the paper referred above weakening |
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113 is done only in axioms. If this radiobutton is switched on (default), |
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114 then, in order to save space, formulae are weakened as soon as possible. |
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115 </UL> |
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116 </TD> |
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117 </TR> |
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118 |
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119 </TABLE> |
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120 <center> |
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121 <!--"CONVERTED_APPLET"--> |
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122 <!-- HTML CONVERTER --> |
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123 <OBJECT classid="clsid:CAFEEFAC-0013-0001-0000-ABCDEFFEDCBA" |
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124 WIDTH = 1 HEIGHT = 1 codebase="http://java.sun.com/products/plugin/1.3.1/jinstall-131-win32.cab#Version=1,3,1,0"> |
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125 <PARAM NAME = CODE VALUE = "MyApplet.class" > |
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126 <PARAM NAME = ARCHIVE VALUE = MyApplet.zip > |
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127 |
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128 <PARAM NAME="type" VALUE="application/x-java-applet;jpi-version=1.3.1"> |
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129 <PARAM NAME="scriptable" VALUE="false"> |
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130 <PARAM NAME = "calculi" VALUE ="B"> |
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131 <COMMENT> |
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132 <EMBED type="application/x-java-applet;jpi-version=1.3.1" CODE = "Cut/MyApplet.class" ARCHIVE = MyApplet.zip WIDTH = 1 HEIGHT = 1 calculi = "B" scriptable=false pluginspage="http://java.sun.com/products/plugin/1.3.1/plugin-install.html"><NOEMBED> |
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133 <p><blink><FONT COLOR="#800000"> |
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134 Applet should appear in a new window, but you don't have Java enabled in your browser. |
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135 </FONT></blink><p> |
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136 </NOEMBED> |
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137 </EMBED> |
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138 </COMMENT> |
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139 </OBJECT> |
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140 |
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141 <!-- |
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142 <APPLET CODE = "Cut/MyApplet.class" ARCHIVE = MyApplet.zip WIDTH = 1 HEIGHT = 1> |
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143 <PARAM NAME = "calculi" VALUE ="B"> |
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144 <p><blink><FONT COLOR="#800000"> |
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145 Applet should appear in a new window, but you don't have Java enabled in your browser. |
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146 </FONT></blink><p> |
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147 |
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148 </APPLET> |
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149 --> |
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150 |
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151 |
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152 <!--"END_CONVERTED_APPLET"--> |
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153 |
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154 |
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155 </center> |
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156 <P><!-- Created: Tue Jul 3 21:01:42 BST 2001 --> |
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157 <!-- hhmts start --> |
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158 Last modified: Sat Mar 3 05:17:20 CET 2007 |
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159 <!-- hhmts end --> |
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160 </BODY> |
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161 </HTML> |