helm/www/lambda_delta/news.html

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   7   <meta content="The formal system lambda-delta" name="description">
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  12 <br>
  13 <a href="http://lambda-delta.info"><img alt="[Crux Logo]"
  14  title="The Crux" src="download/crux_32.png"
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  16 <h1>The Formal System λδ (lambda-delta)<br>
  17 </h1>
  18 <h2>Towards the unification of terms, types, environments and contexts</h2>
  19 <img style="width: 95%; height: 4px;" alt="[Separator]"
  20  title="Separator" src="download/rainbow.png"><br>
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  26       <td style="vertical-align: top;">
  27       <ul>
  28         <li><a href="index.html">Foreword</a></li>
  29       </ul>
  30       <ul>
  31         <li>News</li>
  32       </ul>
  33       <ul>
  34         <li><a href="documentation.html">Papers</a></li>
  35       </ul>
  36       <ul>
  37         <li><a href="implementation.html">Resources</a><br>
  38         </li>
  39       </ul>
  40       </td>
  41       <td style="vertical-align: top; text-align: left;">
  42       <h3 style="text-align: right;">News <img
  43  style="width: 37px; height: 37px;" alt="[Butterfly]" title="Butterfly"
  44  src="download/b5.png"></h3>
  45       <ul>
  46         <li><span style="font-weight: bold;">December 2010.</span>
  47 Permanent λδ URL acquired: <a href="http://lambda-delta.info">http://lambda-delta.info</a>
  48 (pointing at this site). <br>
  49           <span style="font-weight: bold;"></span></li>
  50       </ul>
  51       <ul>
  52         <li><span style="font-weight: bold;">November 2010.</span> <span
  53  style="font-style: italic;">Helena 0.8.1</span> is released. <br>
  54         </li>
  55       </ul>
  56       <ul>
  57         <li><span style="font-weight: bold;">September 2009.</span> <span
  58  style="font-style: italic;">Helena 0.8.0</span> is released and the <a
  59  href="implementation.html#lddl">λδ Digital Library</a> is
  60 started.<br>
  61           <span style="font-weight: bold;"></span></li>
  62       </ul>
  63       <ul>
  64         <li><span style="font-weight: bold;">June 2009.</span> <span
  65  style="font-style: italic;">Helena</span>, A <a
  66  href="implementation.html#helena">validator for </a><a
  67  href="implementation.html#helena">λδ</a><span
  68  style="font-style: italic;"></span>, <span style="font-style: italic;"></span>is
  69 available
  70 as a
  71 part of the <a href="http://helm.cs.unibo.it/">HELM</a> software. <br>
  72         </li>
  73       </ul>
  74       <span style="font-weight: bold;"></span>
  75       <ul>
  76         <li><span style="font-weight: bold;">September 2008.</span>
  77 This site is online.<br>
  78         </li>
  79       </ul>
  80       <span style="font-weight: bold;"></span>
  81       <ul>
  82         <li><span style="font-weight: bold;">July 2008.</span> <a
  83  href="documentation.html#tocl1">First journal paper on λδ</a> accepted
  84 for publication.</li>
  85       </ul>
  86       <ul>
  87         <li><span style="font-weight: bold;">July 2008.</span> First <a
  88  href="http://helm.cs.unibo.it/procedural/">procedural
  89 reconstruction</a> in <a href="http://matita.cs.unibo.it/">Matita 0.5</a>
  90 of the <a href="implementation.html#source">λδ proof scripts in
  91 Coq 7.3.1</a>.<br>
  92         </li>
  93       </ul>
  94       <ul>
  95         <li><span style="font-weight: bold;">June 2008.</span> The <a
  96  href="implementation.html#static">HTML
  97 pages of the specification of λδ in Matita 0.5</a> are online.<br>
  98           <span style="font-weight: bold;"></span></li>
  99       </ul>
 100       <ul>
 101         <li><span style="font-weight: bold;">March 2008.</span> An
 102 improvement of the
 103 specification of λδ in Coq 7.3.1 begins:
 104           <ul>
 105             <li>native type assignment with new rules for application: <span
 106  style="font-style: italic;">nty</span> (it replaces <span
 107  style="font-style: italic;">ty3</span>);<br>
 108             </li>
 109             <li>parallel conversion on focalized terms: <span
 110  style="font-style: italic;">fpcs</span> (it replaces <span
 111  style="font-style: italic;"></span><span style="font-style: italic;">pc3</span>);
 112
 113
 114
 115
 116
 117
 118
 119               <br>
 120             </li>
 121             <li>new weak parallel reduction on environments: <span
 122  style="font-style: italic;">wcpr</span> <span
 123  style="font-style: italic;"></span>(it is based on <span
 124  style="font-style: italic;">fpr</span> and replaces <span
 125  style="font-style: italic;">wcpr0</span>);&nbsp; <br>
 126             </li>
 127             <li>parallel reduction on focalized terms: <span
 128  style="font-style: italic;">fpr</span> and <span
 129  style="font-style: italic;">fprs</span> (they replace <span
 130  style="font-style: italic;"></span><span style="font-style: italic;"></span><span
 131  style="font-style: italic;">pr2</span>, <span
 132  style="font-style: italic;">pr3</span>); <br>
 133             </li>
 134           </ul>
 135           <ul>
 136             <li>new thinning relation: <span
 137  style="font-style: italic;">drop</span>
 138 (it replaces the old <span style="font-style: italic;">drop</span>, <span
 139  style="font-style: italic;">clear</span>, <span
 140  style="font-style: italic;">getl</span>, <span
 141  style="font-style: italic;">cimp</span>, <span
 142  style="font-style: italic;">drop1</span>);</li>
 143             <li>new shift function: <span style="font-style: italic;">shift</span>:
 144 (it
 145 replaces
 146               <span style="font-style: italic;">app1</span>);</li>
 147             <li>new length function for environments: <span
 148  style="font-style: italic;">clen</span>;<br>
 149             </li>
 150             <li>new relocation function: <span
 151  style="font-style: italic;">lift</span> (it replaces old <span
 152  style="font-style: italic;">lift</span>, <span
 153  style="font-style: italic;">lift1</span>);<br>
 154             </li>
 155             <li>new term structure with polarity indicators and no
 156 distinction between binding and flat items;</li>
 157             <li>new general theory of relocation (comprises new
 158 relocation functions: <span style="font-style: italic;">s</span>, <span
 159  style="font-style: italic;">r</span>);</li>
 160             <li>we removed context-free reduction and conversion (<span
 161  style="font-style: italic;">pr0</span>, <span
 162  style="font-style: italic;">pr1</span>, <span
 163  style="font-style: italic;">pc1</span>);<br>
 164             </li>
 165             <li>we removed greedy substitution (<span
 166  style="font-style: italic;"></span><span style="font-style: italic;">csubst0</span>,
 167
 168
 169               <span style="font-style: italic;">csubst1</span>, <span
 170  style="font-style: italic;">fsubst0</span>, <span
 171  style="font-style: italic;">subst0</span>, <span
 172  style="font-style: italic;">subst1</span>);<br>
 173             </li>
 174             <li>we removed level indicators on environments (<span
 175  style="font-style: italic;">cbk</span>).</li>
 176           </ul>
 177         </li>
 178       </ul>
 179       <ul>
 180         <li><span style="font-weight: bold;">September 2007.</span>
 181 The <a href="implementation.html#dynamic">specification of λδ in
 182 Matita 0.4</a> is online.<br>
 183         </li>
 184       </ul>
 185       <ul>
 186         <li><span style="font-weight: bold;">December 2005.</span> <a
 187  href="documentation.html#bologna1">First communication on λδ</a>.<br>
 188         </li>
 189       </ul>
 190       <ul>
 191         <li><span style="font-weight: bold;">May 2004.</span> The <a
 192  href="implementation.html#source">specification of λδ in
 193 Coq 7.3.1</a> begins.<br>
 194         </li>
 195       </ul>
 196       <h3 style="text-align: right;">Visibility <img
 197  style="width: 37px; height: 37px;" alt="[Butterfly]" title="Butterfly"
 198  src="download/b4.png"></h3>
 199       <ul>
 200         <li><span style="font-weight: bold;">November 2010.</span> The <a
 201  href="http://www.google.com/">Google</a>
 202 search <span style="color: rgb(255, 0, 0);">formal system lambda delta</span>
 203 gives 8 resources about λδ as the first results.<br>
 204         </li>
 205       </ul>
 206       <ul>
 207         <li><span style="font-weight: bold;">November 2010.</span> The <a
 208  href="http://www.yahoo.com/">Yahoo</a>
 209 search <span style="color: rgb(255, 0, 0);">formal system lambda delta</span>
 210 gives 4 resources and 2 sub-resources about λδ as the first results.</li>
 211       </ul>
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