<html>
<head>
<meta content="text/html; charset=UTF-8" http-equiv="content-type">
- <title>lambda-delta home page</title>
+ <title>lambda_delta home page</title>
<meta content="Ferruccio Guidi" name="author">
- <meta content="The formal system lambda-delta" name="description">
+ <meta content="The formal system lambda_delta" name="description">
<link rel="shortcut icon" href="download/crux_16.ico">
</head>
<body>
-<div style="text-align: center;">
-<br>
+<div style="text-align: center;"> <br>
<a href="http://lambda-delta.info"><img alt="[Crux Logo]"
title="The Crux" src="download/crux_32.png"
style="border: 0px solid ; width: 32px; height: 32px;"></a>
-<h1>The Formal System λδ (lambda-delta)<br>
+<h1>The Formal System λδ (lambda_delta)<br>
</h1>
<h2>Towards the unification of terms, types, environments and contexts</h2>
<img style="width: 95%; height: 4px;" alt="[Separator]"
<h3 style="text-align: right;">News <img
style="width: 37px; height: 37px;" alt="[Butterfly]" title="Butterfly"
src="download/b5.png"></h3>
+ <ul>
+ <li><span style="font-weight: bold;">September 2011.</span> The
+denomination "lambda-delta" changes to "lambda_delta".
+ <ul>
+ <li>The character "-" is reserved in λδ textual syntax
+(recognized by <span style="font-style: italic;">Helena 0.8.1</span>).
+ </li>
+ <li>Eventually, the occurrences of the character "-" will
+be replaced by "_" in all λδ-related identifiers.</li>
+ <li>In particular, this refactoring involves file names and
+path names.</li>
+ <li>The permanent λδ URL is sheduled to become <span
+ style="font-style: italic;">http://lambda_delta.info</span> on
+December 2012.<br>
+ </li>
+ </ul>
+ </li>
+ </ul>
+ <ul>
+ <li><span style="font-weight: bold;">April 2011.</span> The
+specification of λδ version 2 and related topics is restarted in <a
+ href="http://matita.cs.unibo.it/">Matita 0.5</a>.
+ <ul>
+ <li><a href="apps_2.html">Here</a> is a page about the
+topics related to the specification (Applications).</li>
+ <li><a href="basic_2.html">Here</a> is a page about the
+specification (Core). </li>
+ </ul>
+ </li>
+ </ul>
<ul>
<li><span style="font-weight: bold;">December 2010.</span>
Permanent λδ URL acquired: <a href="http://lambda-delta.info">http://lambda-delta.info</a>
<ul>
<li><span style="font-weight: bold;">September 2009.</span> <span
style="font-style: italic;">Helena 0.8.0</span> is released and the <a
- href="implementation.html#lddl">λδ Digital Library</a> is
-started.<br>
+ href="implementation.html#lddl">λδ Digital Library</a> is started.<br>
<span style="font-weight: bold;"></span></li>
</ul>
<ul>
<li><span style="font-weight: bold;">June 2009.</span> <span
- style="font-style: italic;">Helena</span>, A <a
- href="implementation.html#helena">validator for </a><a
- href="implementation.html#helena">λδ</a><span
- style="font-style: italic;"></span>, <span style="font-style: italic;"></span>is
-available
-as a
-part of the <a href="http://helm.cs.unibo.it/">HELM</a> software. <br>
+ style="font-style: italic;">Helena</span>, a <a
+ href="implementation.html#helena">validator for λδ version 2</a>, is
+available as a part of the <a href="http://helm.cs.unibo.it/">HELM</a>
+software. <br>
</li>
</ul>
<span style="font-weight: bold;"></span>
<span style="font-weight: bold;"></span>
<ul>
<li><span style="font-weight: bold;">July 2008.</span> <a
- href="documentation.html#tocl1">First journal paper on λδ</a> accepted
+ href="documentation.html#ldp5">First journal paper on λδ</a> accepted
for publication.</li>
</ul>
<ul>
<li><span style="font-weight: bold;">July 2008.</span> First <a
- href="http://helm.cs.unibo.it/procedural/">procedural
-reconstruction</a> in <a href="http://matita.cs.unibo.it/">Matita 0.5</a>
-of the <a href="implementation.html#source">λδ proof scripts in
-Coq 7.3.1</a>.<br>
+ href="http://helm.cs.unibo.it/procedural/">procedural reconstruction</a>
+for <a href="http://matita.cs.unibo.it/">Matita 0.5</a> of the <a
+ href="implementation.html#ldp1">λδ proof scripts for Coq 7.3.1</a>.<br>
</li>
</ul>
<ul>
<li><span style="font-weight: bold;">June 2008.</span> The <a
- href="implementation.html#static">HTML
-pages of the specification of λδ in Matita 0.5</a> are online.<br>
+ href="implementation.html#static">HTML pages of the specification of
+λδ version 1 for Matita 0.5</a> are online.<br>
<span style="font-weight: bold;"></span></li>
</ul>
<ul>
- <li><span style="font-weight: bold;">March 2008.</span> An
-improvement of the
-specification of λδ in Coq 7.3.1 begins:
- <ul>
+ <li><span style="font-weight: bold;">May 2008.</span> The
+specification of λδ version 1 is closed.<br>
+ <span style="font-weight: bold;"></span></li>
+ </ul>
+ <ul>
+ <li><span style="font-weight: bold;">March 2008.</span> The
+specification of λδ version 2 is started with Coq 7.3.1 (false start). </li>
+ </ul>
+<!-- <ul>
<li>native type assignment with new rules for application: <span
style="font-style: italic;">nty</span> (it replaces <span
style="font-style: italic;">ty3</span>);<br>
<li>parallel conversion on focalized terms: <span
style="font-style: italic;">fpcs</span> (it replaces <span
style="font-style: italic;"></span><span style="font-style: italic;">pc3</span>);
-
-
-
-
-
-
-
<br>
</li>
<li>new weak parallel reduction on environments: <span
<li>new shift function: <span style="font-style: italic;">shift</span>:
(it
replaces
+
<span style="font-style: italic;">app1</span>);</li>
<li>new length function for environments: <span
style="font-style: italic;">clen</span>;<br>
</li>
<li>we removed greedy substitution (<span
style="font-style: italic;"></span><span style="font-style: italic;">csubst0</span>,
-
-
<span style="font-style: italic;">csubst1</span>, <span
style="font-style: italic;">fsubst0</span>, <span
style="font-style: italic;">subst0</span>, <span
<li>we removed level indicators on environments (<span
style="font-style: italic;">cbk</span>).</li>
</ul>
- </li>
+-->
+ <ul>
+ <li><span style="font-weight: bold;">September 2007.</span> The
+ <a href="implementation.html#dynamic">specification of λδ
+version 1 for Matita 0.4</a> is online.</li>
</ul>
<ul>
- <li><span style="font-weight: bold;">September 2007.</span>
-The <a href="implementation.html#dynamic">specification of λδ in
-Matita 0.4</a> is online.<br>
- </li>
+ <li><span style="font-weight: bold;">November 2006.</span> <a
+ href="documentation.html#ldp3">λδ version 1</a> is released.</li>
</ul>
<ul>
<li><span style="font-weight: bold;">December 2005.</span> <a
- href="documentation.html#bologna1">First communication on λδ</a>.<br>
+ href="documentation.html#ldt1">First communication on λδ</a>.<br>
</li>
</ul>
<ul>
<li><span style="font-weight: bold;">May 2004.</span> The <a
- href="implementation.html#source">specification of λδ in
-Coq 7.3.1</a> begins.<br>
+ href="implementation.html#ldp1">specification of λδ version 1</a> is
+started with Coq 7.3.1.<br>
</li>
</ul>
<h3 style="text-align: right;">Visibility <img
style="width: 37px; height: 37px;" alt="[Butterfly]" title="Butterfly"
src="download/b4.png"></h3>
<ul>
- <li><span style="font-weight: bold;">
November 2010.</span> The <a
- href="http://www.google.com/">Google</a>
-search <span style="color: rgb(255, 0, 0);">formal system lambda delta</span>
-gives 8 resources about λδ as the first results.<br>
+ <li><span style="font-weight: bold;">
February 2012.</span> The <a
+ href="http://www.google.com/">Google</a> search for <span
+ style="color: rgb(255, 0, 0);">formal system lambda delta</span> gives
+5 resources about λδ in the first 6 results.<br>
</li>
</ul>
<ul>
- <li><span style="font-weight: bold;">
November 2010.</span> The <a
- href="http://www.yahoo.com/">Yahoo</a>
-search <span style="color: rgb(255, 0, 0);">formal system lambda delta</span>
-gives 4 resources and 2 sub-resources about λδ as the first results.</li>
+ <li><span style="font-weight: bold;">
February 2012.</span> The <a
+ href="http://www.yahoo.com/">Yahoo</a> search <span
+ style="color: rgb(255, 0, 0);">formal system lambda delta</span> gives
+this site as the first result.</li>
</ul>
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-Last update 2010-12-14 by <a href="http://www.cs.unibo.it/%7Efguidi/">Ferruccio
+Last update 2012-11-20 by <a href="http://www.cs.unibo.it/%7Efguidi/">Ferruccio
+
Guidi</a><br>
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projects / helm.git / blobdiff