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22 <div class="head1">The Formal Systems of the λδ (\lambda\delta) Family</div>
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34 <a href="http://lambdadelta.info/index.html">home</a>
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37 <a href="http://lambdadelta.info/news.html">news</a>
39 <td class="snns capitalize italic white">
40 <a href="http://lambdadelta.info/specification.html">specification</a>
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49 <a href="http://lambdadelta.info/documentation.html">documentation</a>
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52 <a href="http://lambdadelta.info/implementation.html">implementation</a>
54 <td class="ssnn capitalize italic green">
59 <td class="snns capitalize sky">
60 <a href="http://lambdadelta.info/index.html#foreword">foreword</a>
62 <td class="snns capitalize magenta">
63 <a href="http://lambdadelta.info/news.html#milestones">milestones</a>
65 <td class="snns capitalize white">
66 <a href="http://lambdadelta.info/specification.html#v2">version 2</a>
68 <td class="snnn capitalize white">(<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>
69 <td class="snnn capitalize white">
72 <td class="snns capitalize orange">
73 <a href="http://lambdadelta.info/documentation.html#v2">version 2</a>
75 <td class="snns capitalize green">
76 <a href="http://lambdadelta.info/implementation.html#lddl">library</a>
78 <td class="ssnn capitalize green">(<a href="http://lambdadelta.info/static/lddl/">static LDDL directory</a>)</td>
81 <td class="snss capitalize sky">
82 <a href="http://lambdadelta.info/index.html#citations">citations</a>
84 <td class="snss capitalize magenta">
85 <a href="http://lambdadelta.info/news.html#visibility">visibility</a>
87 <td class="snss capitalize white">
88 <a href="http://lambdadelta.info/specification.html#v1">version 1</a>
90 <td class="snsn capitalize white">(<a href="http://lambdadelta.info/ground_1.html">background</a> - <a href="http://lambdadelta.info/basic_1.html">core</a>)</td>
91 <td class="snsn capitalize white">(<a href="http://lambdadelta.info/static/matita/lambdadelta/">static HELM directory</a>)</td>
92 <td class="snss capitalize orange">
93 <a href="http://lambdadelta.info/documentation.html#v1">version 1</a>
95 <td class="snss capitalize green">
96 <a href="http://lambdadelta.info/implementation.html#helena">helena</a>
98 <td class="sssn capitalize green">
105 <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/b15.png" />
107 <div xmlns:ld="http://lambdadelta.info/" class="text">
108 The systems of the λδ family are developed as machine-checked digital specifications,
109 and are listed in the next table, which includes the major milestones.
111 <div xmlns:ld="http://lambdadelta.info/" class="text">
112 The life cycle of a specification consists of four periods.
113 <span class="emph alpha">Alpha:</span>
114 the definitions are designed and the major propositions are proved,
115 then the calculus is announced with a presentation.
116 <span class="emph beta">Beta:</span>
117 major changes and additions may occur before the calculus is released on paper.
118 <span class="emph gamma">Gamma:</span>
119 subsequent improvements occur until the specification is completed or superseded,
120 while major changes and additions are announced and reported on paper.
121 <span class="emph delta">Delta:</span>
122 after its conclusion, the specification is modified just for maintenance.
124 <div xmlns:ld="http://lambdadelta.info/" class="text">
125 <table cellpadding="4" cellspacing="0">
128 <td class="snns top capitalize italic gray">version</td>
129 <td class="snnn top capitalize italic gray">name</td>
130 <td class="snnn top capitalize italic gray">developed with</td>
131 <td class="snnn top capitalize italic gray">stage</td>
132 <td class="snnn top capitalize italic gray">started</td>
133 <td class="snnn top capitalize italic gray">announced</td>
134 <td class="snnn top capitalize italic gray">released</td>
135 <td class="snnn top capitalize italic gray">concluded</td>
136 <td class="ssnn top capitalize italic gray">references</td>
139 <td class="snns top orange">
140 <a href="http://lambdadelta.info/specification.html#v2">Version 2</a>
142 <td class="snnn top orange">"basic_2"</td>
143 <td class="snnn top orange">
144 <a href="http://matita.cs.unibo.it/">Matita 0.99.2</a>
146 <td class="snns top orange">"A2"</td>
147 <td class="snnn top orange">October 2015</td>
148 <td class="snnn top orange" />
149 <td class="snnn top orange" />
150 <td class="snnn top orange" />
151 <td class="ssnn top orange">
156 <td class="nnns top orange">
159 <td class="nnnn top orange">
162 <td class="nnnn top orange">
165 <td class="snns top orange">"A1"</td>
166 <td class="snnn top orange">April 2011</td>
167 <td class="snnn top orange">June 2014</td>
168 <td class="snnn top orange">October 2014</td>
169 <td class="snnn top orange">August 2015</td>
170 <td class="ssnn top orange">
171 <a href="http://lambdadelta.info/documentation#ldV2a">V2a</a>
172 <a href="http://lambdadelta.info/documentation#ldR2c">R2c</a>
176 <td class="snns top orange">Abandoned</td>
177 <td class="snnn top orange" />
178 <td class="snnn top orange">
179 <a href="http://coq.inria.fr/">Coq 7.3.1</a>
181 <td class="snnn top orange" />
182 <td class="snnn top orange">March 2008</td>
183 <td class="snnn top orange" />
184 <td class="snnn top orange" />
185 <td class="snnn top orange">February 2011</td>
186 <td class="ssnn top orange">
191 <td class="snss top red">
192 <a href="http://lambdadelta.info/specification.html#v1">Version 1</a>
194 <td class="snsn top red">"basic_1"</td>
195 <td class="snsn top red">
196 <a href="http://coq.inria.fr/">Coq 7.3.1</a>
198 <td class="snsn top red" />
199 <td class="snsn top red">May 2004</td>
200 <td class="snsn top red">December 2005</td>
201 <td class="snsn top red">November 2006</td>
202 <td class="snsn top red">May 2008</td>
203 <td class="sssn top red">
204 <a href="http://lambdadelta.info/documentation#ldV1a">V1a</a>
205 <a href="http://lambdadelta.info/documentation#ldJ1a">J1a</a>
211 <div xmlns:ld="http://lambdadelta.info/" class="text">
212 Informational pages on the specifications are provided.
214 <ul xmlns:ld="http://lambdadelta.info/" id="">
216 <span class="emph alpha">Notice on displayed numerical acounts:</span>
217 nodes are counted according to the "intrinsic complexity measure"
218 [F. Guidi: "Procedural Representation of CIC Proof Terms"
219 Journal of Automated Reasoning 44(1-2), Springer (February 2010), pp. 53-78].
222 <ul xmlns:ld="http://lambdadelta.info/" id="">
224 <span class="emph alpha">Notice on displayed logical structures:</span>
225 from the logical standpoint, the source scripts are grouped in "planes"
226 and these are grouped in "components";
227 the notation for the relations or functions
228 introduced in each script, is shown in parentheses (? are placeholders).
231 <!-- VERSION 2 =========================================================== -->
232 <div xmlns:ld="http://lambdadelta.info/" class="head3sn" id="v2">
233 <img class="icon37" alt="[spacer]" title="lambdadelta butterfly" src="http://lambdadelta.info/images/b4.png" /> λδ version 2 (active)</div>
234 <div xmlns:ld="http://lambdadelta.info/" class="text">
235 The formal specification of λδ version 2
236 is available in the following formats:
238 <ul xmlns:ld="http://lambdadelta.info/" id="source2">
241 <a href="http://lambdadelta.info/download/lambdadelta_2A1.tar.gz">lambdadelta_2A1 for Matita 0.99.2</a>
242 (revised <span class="emph gamma">2014-10</span>).
244 <a href="http://lambdadelta.info/documentation.html#ldR2c">Documentation (R2c)</a>.
247 The scripts are grouped in directories, first by part, then by component.
250 <span class="emph alpha">Notice:</span>
251 the scripts are checked by the latest version of Matita from
252 <a href="http://matita.cs.unibo.it/download.shtml">HELM Subversion repository</a>
253 at path <trunk/matita/>.
257 <div xmlns:ld="http://lambdadelta.info/" class="text">
258 Informational pages on the parts of the specification:
259 <a href="http://lambdadelta.info/ground_2.html">Background</a>,
260 <a href="http://lambdadelta.info/basic_2.html">Core</a>,
261 <a href="http://lambdadelta.info/apps_2.html">Applications</a>.
263 <!-- VERSION 1 =========================================================== -->
264 <div xmlns:ld="http://lambdadelta.info/" class="head3sn" id="v1">
265 <img class="icon37" alt="[spacer]" title="lambdadelta butterfly" src="http://lambdadelta.info/images/b6.png" /> λδ version 1 (superseded)</div>
266 <div xmlns:ld="http://lambdadelta.info/" class="text">
267 The formal specification of λδ version 1
268 is available in the following formats:
270 <ul xmlns:ld="http://lambdadelta.info/" id="source1">
273 <a href="http://lambdadelta.info/download/lambdadelta_1.tar.gz">lambdadelta_1 for Coq 7.3.1</a>
274 (revised <span class="emph delta">2015-09</span>).
276 <a href="http://lambdadelta.info/documentation.html#ldJ1a">Documentation (J1a)</a>.
279 <span class="emph delta">2015 January 15.</span>
280 17 new lemmas and former lemma "eq_nat_dec" renamed as "nat_dec_neg".
285 The scripts are grouped in directories, one for each part.
289 <ul xmlns:ld="http://lambdadelta.info/" id="static1">
291 <a href="http://lambdadelta.info/static/matita/lambdadelta/">lambdadelta_1 for Matita 0.5</a>
292 (revised <span class="emph delta">2011-09</span>).
293 Static HTML pages generated by the <a href="http://helm.cs.unibo.it/">HELM</a> rendering engine.
296 <a href="http://lambdadelta.info/static/matita/lambdadelta/basic_1/pr3/pr3/pr3_confluence.con.html">
297 Confluence of reduction</a>
298 (Church-Rosser property).
301 <a href="http://lambdadelta.info/static/matita/lambdadelta/basic_1/ty3/props/ty3_correct.con.html">
302 Correctness of types</a>.
305 <a href="http://lambdadelta.info/static/matita/lambdadelta/basic_1/ty3/props/ty3_unique.con.html">
306 Uniqueness of types up to conversion</a>.
309 <a href="http://lambdadelta.info/static/matita/lambdadelta/basic_1/ty3/pr3/ty3_sred_pr3.con.html">
310 Subject reduction of the type assignment</a>.
313 <a href="http://lambdadelta.info/static/matita/lambdadelta/basic_1/ty3/arity_props/ty3_sn3.con.html">
314 Strong normalization of the typed terms</a>.
317 <a href="http://lambdadelta.info/static/matita/lambdadelta/basic_1/ty3/dec/ty3_inference.con.html">
318 Decidability of the type inference problem</a>.
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326 lambdadelta_1 for Matita 0.5</a>
327 (revised <span class="emph delta">2011-09</span>).
328 <a href="http://helm.cs.unibo.it/">HELM</a> directory.
329 <span class="emph alpha">Notice: the HELM rendering engine is offline.</span>
332 <div xmlns:ld="http://lambdadelta.info/" class="text">
333 Informational pages on the parts of the specification:
334 <a href="http://lambdadelta.info/ground_1.html">Background</a>,
335 <a href="http://lambdadelta.info/basic_1.html">Core</a>.
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363 <div xmlns:ld="http://lambdadelta.info/" class="spacer">Last update: Wed, 30 Dec 2015 12:08:04 +0100</div>