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10 <title>\lambda\delta home page</title>
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22 <div class="head1">The Formal System λδ (\lambda\delta)</div>
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26 <div xmlns:ld="http://lambdadelta.info/" class="spacer">
29 <div xmlns:ld="http://lambdadelta.info/" class="text">
30 <table cellpadding="4" cellspacing="0">
33 <td class="snns capitalize italic sky">
34 <a href="http://lambdadelta.info/index.html">home</a>
36 <td class="snns capitalize italic magenta">
37 <a href="http://lambdadelta.info/news.html">news</a>
39 <td class="snns capitalize italic orange">
40 <a href="http://lambdadelta.info/documentation.html">documentation</a>
42 <td class="snns capitalize italic green">
43 <a href="http://lambdadelta.info/specification.html">specification</a>
45 <td class="snnn capitalize italic green">
48 <td class="ssns capitalize italic green">
49 <a href="http://lambdadelta.info/implementation.html">implementation</a>
53 <td class="snns capitalize sky">
54 <a href="http://lambdadelta.info/index.html#foreword">foreword</a>
56 <td class="snns capitalize magenta">
57 <a href="http://lambdadelta.info/news.html#milestones">milestones</a>
59 <td class="snns capitalize orange">
60 <a href="http://lambdadelta.info/documentation.html#v2">version 2</a>
62 <td class="snns capitalize green">
63 <a href="http://lambdadelta.info/specification.html#v2">version 2</a>
65 <td class="snnn capitalize green">(<a href="http://lambdadelta.info/ground_2.html">background</a> - <a href="http://lambdadelta.info/basic_2.html">core</a> - <a href="http://lambdadelta.info/apps_2.html">applications</a>)</td>
66 <td class="ssns capitalize green">
67 <a href="http://lambdadelta.info/implementation.html#lddl">library</a>
71 <td class="snss capitalize sky">
72 <a href="http://lambdadelta.info/index.html#notice">notice</a>
74 <td class="snss capitalize magenta">
75 <a href="http://lambdadelta.info/news.html#citations">citations</a>
77 <td class="snss capitalize orange">
78 <a href="http://lambdadelta.info/documentation.html#v1">version 1</a>
80 <td class="snss capitalize green">
81 <a href="http://lambdadelta.info/specification.html#v1">version 1</a>
83 <td class="snsn capitalize green">
86 <td class="ssss capitalize green">
87 <a href="http://lambdadelta.info/implementation.html#helena">helena</a>
94 <div xmlns:ld="http://lambdadelta.info/" class="head2dx" id="specifications">Computer-checked formal specifications <img class="icon37" alt="[spacer]" title="lambdadelta butterfly" src="http://lambdadelta.info/images/b5.png" />
96 <div xmlns:ld="http://lambdadelta.info/" class="text">
97 λδ is developed as a machine-checked digital specification.
98 It comes in several versions listed in the next table,
99 which includes the major milestones:
101 <div xmlns:ld="http://lambdadelta.info/" class="text">
102 <table cellpadding="4" cellspacing="0">
105 <td class="snns top capitalize italic gray">version</td>
106 <td class="snnn top capitalize italic gray">name</td>
107 <td class="snnn top capitalize italic gray">developed with</td>
108 <td class="snnn top capitalize italic gray">stage</td>
109 <td class="snnn top capitalize italic gray">started</td>
110 <td class="snnn top capitalize italic gray">announced</td>
111 <td class="snnn top capitalize italic gray">released</td>
112 <td class="ssnn top capitalize italic gray">dismissed</td>
115 <td class="snns top orange">
116 <a href="http://lambdadelta.info/specification.html#v2">Version 2</a>
118 <td class="snnn top orange">"basic_2"</td>
119 <td class="snnn top orange">
120 <a href="http://matita.cs.unibo.it/">Matita 0.99.2</a>
122 <td class="snnn top orange">"A"</td>
123 <td class="snnn top orange">April 2011</td>
124 <td class="snnn top orange">June 2014</td>
125 <td class="snnn top orange">October 2014</td>
126 <td class="ssnn top orange">No</td>
129 <td class="snss top red">
130 <a href="http://lambdadelta.info/specification.html#v1">Version 1</a>
132 <td class="snsn top red">"basic_1"</td>
133 <td class="snsn top red">
134 <a href="http://coq.inria.fr/">Coq 7.3.1</a>
136 <td class="snsn top red" />
137 <td class="snsn top red">May 2004</td>
138 <td class="snsn top red">December 2005</td>
139 <td class="snsn top red">November 2006</td>
140 <td class="sssn top red">May 2008</td>
148 <div xmlns:ld="http://lambdadelta.info/" class="head3sn" id="v2">
149 <img class="icon37" alt="[spacer]" title="lambdadelta butterfly" src="http://lambdadelta.info/images/b4.png" /> λδ version 2 (ongoing)</div>
150 <div xmlns:ld="http://lambdadelta.info/" class="text">
151 The formal specification of λδ version 2
152 is available in the following formats:
155 <ul xmlns:ld="http://lambdadelta.info/" id="source2">
158 <a href="http://lambdadelta.info/download/lambdadelta_2.tar.gz">lambdadelta_2 for Matita 0.99.2</a>
159 (revised <span class="date">2014-10</span>).
163 The scripts are grouped in directories, first by part, then by component.
166 <span class="date">Notice:</span>
167 the scripts are checked by the latest version of Matita from
168 <a href="http://matita.cs.unibo.it/download.shtml">HELM Subversion repository</a>
169 at path <trunk/matita/>.
174 <div xmlns:ld="http://lambdadelta.info/" class="text">
175 Informational pages on the parts of the specification:
176 <a href="http://lambdadelta.info/ground_2.html">Background</a>,
177 <a href="http://lambdadelta.info/basic_2.html">Core</a>,
178 <a href="http://lambdadelta.info/apps_2.html">Applications</a>.
180 <div xmlns:ld="http://lambdadelta.info/" class="text">
181 <span class="date">Notice on numerical acounts:</span>
182 nodes are counted according to the "intrinsic complexity measure"
183 [F. Guidi: "Procedural Representation of CIC Proof Terms"
184 Journal of Automated Reasoning 44(1-2), Springer (February 2010), pp. 53-78].
189 <div xmlns:ld="http://lambdadelta.info/" class="head3sn" id="v1">
190 <img class="icon37" alt="[spacer]" title="lambdadelta butterfly" src="http://lambdadelta.info/images/b6.png" /> λδ version 1 (dismissed)</div>
191 <div xmlns:ld="http://lambdadelta.info/" class="text">
192 The formal specification of λδ version 1
193 is available in the following formats:
196 <ul xmlns:ld="http://lambdadelta.info/" id="source1">
199 <a href="http://lambdadelta.info/download/lambdadelta_1.tar.gz">lambdadelta_1 for Coq 7.3.1</a>
200 (revised <span class="date">2012-10</span>).
204 The scripts are grouped in directories, one for each part.
209 <ul xmlns:ld="http://lambdadelta.info/" id="static1">
211 <a href="http://lambdadelta.info/static/matita/lambdadelta/">lambdadelta_1 for Matita 0.5</a>
212 (revised <span class="date">2011-09</span>).
213 Static HTML pages generated by the <a href="http://helm.cs.unibo.it/">HELM</a> rendering engine.
216 <a href="http://lambdadelta.info/static/matita/lambdadelta/basic_1/pr3/pr3/pr3_confluence.con.html">
217 Confluence of reduction</a>
218 (Church-Rosser property).
221 <a href="http://lambdadelta.info/static/matita/lambdadelta/basic_1/ty3/props/ty3_correct.con.html">
222 Correctness of types</a>.
225 <a href="http://lambdadelta.info/static/matita/lambdadelta/basic_1/ty3/props/ty3_unique.con.html">
226 Uniqueness of types up to conversion</a>.
229 <a href="http://lambdadelta.info/static/matita/lambdadelta/basic_1/ty3/pr3/ty3_sred_pr3.con.html">
230 Subject reduction of the type assignment</a>.
233 <a href="http://lambdadelta.info/static/matita/lambdadelta/basic_1/ty3/arity_props/ty3_sn3.con.html">
234 Strong normalization of the typed terms</a>.
237 <a href="http://lambdadelta.info/static/matita/lambdadelta/basic_1/ty3/dec/ty3_inference.con.html">
238 Decidability of the type inference problem</a>.
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247 lambdadelta_1 for Matita 0.5</a>
248 (revised <span class="date">2011-09</span>).
249 <a href="http://helm.cs.unibo.it/">HELM</a> directory.
250 <span class="date">Notice: the HELM rendering engine is offline.</span>
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280 <div xmlns:ld="http://lambdadelta.info/" class="spacer">Last update: Wed, 22 Oct 2014 20:08:56 +0200</div>