1 <?xml version="1.0" encoding="UTF-8"?>
3 <page xmlns="http://lambdadelta.info/"
4 description = "\lambda\delta home page"
5 title = "\lambda\delta home page"
7 head = "The Formal Systems of the λδ (\lambda\delta) Family"
9 <sitemap name="sitemap"/>
11 <!-- ===================================================================== -->
13 <section3 name="milestones">Milestones</section3>
15 <news class="delta" date="November 2019.">
16 The specifications of λδ-1A and λδ-2A are repackaged
17 (they were λδ-1 and λδ-2A1 respectively).
20 <news class="gamma" date="November 2019.">
22 <rlink to="html/specification.html#source2B">λδ-2B</rlink>
26 <news class="beta" date="November 2018.">
28 <rlink to="html/documentation.html#ldP2e">λδ-2B</rlink>
32 <news class="alpha" date="December 2015.">
33 <rlink to="html/documentation.html#ldJ3a">Second journal paper on λδ</rlink>
34 accepted for publication.
37 <news class="gamma" date="December 2015.">
38 <rlink to="html/implementation.html#v3">"Helena 0.8.3"</rlink> is released.
41 <news class="alpha" date="October 2015.">
42 The specification of λδ-2B is started.
45 <news class="delta" date="August 2015.">
46 The specification of λδ-2A is concluded.
49 <news class="gamma" date="June 2015.">
50 The corrected specification of Landau's "Grundlagen der Analysis"
51 is validated in a λProlog implementation of λδ-3.
54 <news class="delta" date="March 2015.">
55 The specification of λδ-1A is validated by
56 <link to="http://matita.cs.unibo.it/">Matita 0.99.2</link>.
59 <news class="gamma" date="February 2015.">
60 <rlink to="html/implementation.html#v2">"Helena 0.8.2"</rlink> is updated.
62 The translated specification of Landau's "Grundlagen der Analysis"
63 is validated in CC by <link to="http://coq.inria.fr/">Coq 8.4.3</link>.
67 <news class="delta" date="January 2015.">
68 The specification of <rlink to="html/specification.html#v1">λδ-1A</rlink>
69 is updated with backports from the abandoned specification of λδ-2.
72 <news class="gamma" date="December 2014.">
73 <rlink to="html/implementation.html#v2">"Helena 0.8.2"</rlink> is released.
75 The corrected specification of Landau's "Grundlagen der Analysis"
80 <news class="gamma" date="October 2014.">
82 <rlink to="html/specification.html#source2A">λδ-2A</rlink>
86 <news class="beta" date="July 2014.">
87 A new version of this site is online.
90 <news class="beta" date="June 2014.">
92 <rlink to="html/documentation.html#ldP2c">λδ-2A</rlink>
96 <news class="alpha" date="December 2012.">
97 The character "_" is removed from the denomination "lambda_delta":
99 The denomination "\lambda\delta" is used in λδ-related texts.
101 The denomination "lambdadelta" is used in λδ-related identifiers.
103 Permanent λδ URL acquired:
104 <rlink to="">http://lambdadelta.info/</rlink>
105 (pointing at this site).
109 <news class="alpha" date="September 2011.">
110 The denomination "lambda-delta" changes to "lambda_delta":
112 The character "-" is reserved in λδ textual syntax
113 (recognized by "Helena 0.8.1").
115 Eventually, the occurrences of the character "-"
116 will be replaced by "_" in all λδ-related identifiers.
118 In particular, this refactoring involves file names and path names.
122 <news class="alpha" date="April 2011.">
124 <rlink to="html/specification.html#v2">λδ-2</rlink>
125 and related topics is restarted in
126 <link to="http://matita.cs.unibo.it/">Matita 0.5</link>.
129 <news class="delta" date="February 2011.">
130 The specification of λδ-2 with Coq 7.3.1 is abandoned.
133 <news class="alpha" date="December 2010.">
134 Transient λδ URL acquired: http://lambda-delta.info/ (expires on December 2012).
137 <news class="beta" date="November 2010.">
138 <rlink to="html/implementation.html#v1">"Helena 0.8.1"</rlink> is released.
141 <news class="beta" date="September 2009.">
142 <rlink to="html/implementation.html#v0">"Helena 0.8.0"</rlink> is released and the
143 <rlink to="html/implementation.html#lddl">λδ Digital Library</rlink> is started.
146 <news class="alpha" date="June 2009.">
147 "Helena", a <rlink to="html/implementation.html#helena">validator for λδ-2</rlink>,
148 is available as a part of the <link to="http://helm.cs.unibo.it/">HELM</link> software.
151 <news class="alpha" date="September 2008.">
155 <news class="delta" date="July 2008.">
156 <rlink to="html/documentation.html#ldJ1a">First journal paper on λδ</rlink>
157 accepted for publication.
160 <news class="delta" date="July 2008.">
161 First <link to="http://helm.cs.unibo.it/procedural/">procedural reconstruction</link>
162 for <link to="http://matita.cs.unibo.it/">Matita 0.5</link>
163 of the λδ-1A for Coq 7.3.1.
166 <news class="delta" date="June 2008.">
167 The <rlink to="html/specification.html#static1A">
168 HTML pages of the specification of λδ-1A for Matita 0.5</rlink>
172 <news class="delta" date="May 2008.">
173 The specification of λδ-1A is concluded.
176 <news class="alpha" date="March 2008.">
177 The specification of λδ-2 is started with Coq 7.3.1 (false start).
180 <news class="gamma" date="September 2007.">
181 The <rlink to="html/specification.html#dynamic1A">
182 specification of λδ-1A for Matita 0.4</rlink>
186 <news class="gamma" date="November 2006.">
188 <rlink to="html/specification.html#source1A">λδ-1A</rlink>
192 <news class="beta" date="December 2005.">
194 <rlink to="html/documentation.html#ldP1a">λδ-1A</rlink>
198 <news class="alpha" date="May 2004.">
199 The specification of <rlink to="html/specification.html#v1">λδ-1</rlink>
200 is started with Coq 7.3.1.
203 <!-- ===================================================================== -->
205 <section3 name="visibility">Visibility</section3>
207 <news class="alpha" date="November 2019.">
208 The <link to="http://www.google.com/">Google</link>
209 search for "formal system lambda delta" gives
210 9 resources about the λδ family in the first 10 results.
213 <news class="alpha" date="November 2019.">
214 The <link to="http://www.yahoo.com/">Yahoo</link>
215 search for "formal system lambda delta" gives
216 14 resources about the λδ family in the first 14 results.