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 <section15 name="specifications">Computer-checked formal specifications</section15>
13 The systems of the λδ family are developed as machine-checked digital specifications,
14 and are listed in the next table, which includes the major milestones.
17 The life cycle of a specification consists of four periods.
18 <notice class="alpha" text="Alpha:"/>
19 the definitions are designed and the major propositions are proved,
20 then the calculus is announced with a presentation.
21 <notice class="beta" text="Beta:"/>
22 major changes and additions may occur before the calculus is released on paper.
23 <notice class="gamma" text="Gamma:"/>
24 subsequent improvements occur until the specification is completed or superseded,
25 while major changes and additions are announced and reported on paper.
26 <notice class="delta" text="Delta:"/>
27 after its conclusion, the specification is modified just for maintenance.
29 <table name="versions"/>
32 Informational pages on the specifications are provided.
34 <topitem name="notice1">
35 <notice class="alpha" text="Notice on displayed numerical acounts:"/>
36 nodes are counted according to the "intrinsic complexity measure"
37 [F. Guidi: "Procedural Representation of CIC Proof Terms"
38 Journal of Automated Reasoning 44(1-2), Springer (February 2010), pp. 53-78].
40 <topitem name="notice2">
41 <notice class="alpha" text="Notice on displayed logical structures:"/>
42 from the logical standpoint, the source scripts are grouped in "planes"
43 and these are grouped in "components";
44 the notation for the relations or functions
45 introduced in each script, is shown in parentheses (? are placeholders).
48 <!-- VERSION 3 =========================================================== -->
50 <subsection name="v3"><img logo="ld3"/>λδ version 3 (proposed)</subsection>
52 The formal specification of λδ version 3
56 <!-- VERSION 2 =========================================================== -->
58 <subsection name="v2"><img logo="ld2"/>λδ version 2 (active)</subsection>
60 The formal specification of λδ version 2
61 is available in the following formats.
65 Informational pages on the parts of the specification:
66 <rlink to="html/ground_2.html">Background</rlink>,
67 <rlink to="html/static_2.html">Syntax</rlink>,
68 <rlink to="html/basic_2.html">Core</rlink>,
69 <rlink to="html/apps_2.html">Applications</rlink>.
73 <notice class="alpha" text="Notice:"/>
74 The scripts are grouped in directories, first by part, then by component.
78 <notice class="alpha" text="Notice:"/>
79 the scripts are checked by the latest version of Matita from
80 <link to="http://matita.cs.unibo.it/gitweb/?p=helm.git;a=summary">HELM Git repository</link>.
83 <topitem name="source2B">
85 <rlink to="download/lambdadelta_2B.tar.bz2">lambdadelta_2B for Matita 0.99.4</rlink>
86 (revised <notice class="gamma" text="2019-11"/>).
87 Source scripts [Git revision: 2019-11-19 20:45:15].
88 <rlink to="html/documentation.html#ldJ2a">Documentation (J2a)</rlink>.
92 <topitem name="source2A">
94 <rlink to="download/lambdadelta_2A.tar.bz2">lambdadelta_2A for Matita 0.99.2</rlink>
95 (revised <notice class="delta" text="2019-11"/>).
96 Source scripts [Git revision: 2014-10-28 17:46:26].
97 <rlink to="html/documentation.html#ldR2c">Documentation (R2c)</rlink>.
99 <notice class="delta" text="2019 November 20."/>
100 repackaging (was lambdadelta_2A1).
105 <!-- VERSION 1 =========================================================== -->
107 <subsection name="v1"><img logo="ld1"/>λδ version 1 (superseded)</subsection>
109 The formal specification of λδ version 1
110 is available in the following formats.
114 Informational pages on the parts of the specification:
115 <rlink to="html/ground_1.html">Background</rlink>,
116 <rlink to="html/basic_1.html">Core</rlink>.
120 <notice class="alpha" text="Notice:"/>
121 The scripts are grouped in directories, one for each part.
124 <topitem name="source1A">
126 <rlink to="download/lambdadelta_1A.tar.bz2">lambdadelta_1A for Coq 7.3.1</rlink>
127 (revised <notice class="delta" text="2019-11"/>).
129 <rlink to="html/documentation.html#ldJ1a">Documentation (J1a)</rlink>.
131 <notice class="delta" text="2019 November 20."/>
132 repackaging (was lambdadelta_1).
134 <notice class="delta" text="2015 January 15."/>
135 17 new lemmas and former lemma "eq_nat_dec" renamed as "nat_dec_neg".
140 <topitem name="static1A">
141 <rlink to="static/matita/lambdadelta/">lambdadelta_1A for Matita 0.5</rlink>
142 (revised <notice class="delta" text="2019-11"/>).
143 Static HTML pages generated by the <link to="http://helm.cs.unibo.it/">HELM</link> rendering engine.
145 <rlink to="static/matita/lambdadelta/basic_1/pr3/pr3/pr3_confluence.con.html">
146 Confluence of reduction</rlink>
147 (Church-Rosser property).
149 <rlink to="static/matita/lambdadelta/basic_1/ty3/props/ty3_correct.con.html">
150 Correctness of types</rlink>.
152 <rlink to="static/matita/lambdadelta/basic_1/ty3/props/ty3_unique.con.html">
153 Uniqueness of types up to conversion</rlink>.
155 <rlink to="static/matita/lambdadelta/basic_1/ty3/pr3/ty3_sred_pr3.con.html">
156 Subject reduction of the type assignment</rlink>.
158 <rlink to="static/matita/lambdadelta/basic_1/ty3/arity_props/ty3_sn3.con.html">
159 Strong normalization of the typed terms</rlink>.
161 <rlink to="static/matita/lambdadelta/basic_1/ty3/dec/ty3_inference.con.html">
162 Decidability of the type inference problem</rlink>.
166 <topitem name="dynamic1A">
167 <link to="http://mowgli.cs.unibo.it:58080/apply?keys=RT&xmluri=http://helm.cs.unibo.it/helm//html/folder/index.html&prop.media-type=text/html&param.thmedia-type=text/html&param.thkeys=T1%2CT2%2CL%2CE&param.embedkeys=d_c%2CTC1%2CHC2%2CL&param.thencoding=UTF-8&prop.encoding=UTF-8&prop.doctype-public=-//W3C//DTD%20XHTML%201.0%20Transitional//EN&param.doctype-public=-//W3C//DTD%20XHTML%201.0%20Transitional//EN&param.encoding=UTF-8&param.media-type=text/html&param.keys=d_c%2CC1%2CHC2%2CL&profile=default&param.profile=default&param.CICURI=theory:/matita/lambdadelta/">
168 lambdadelta_1A for Matita 0.5</link>
169 (revised <notice class="delta" text="2019-11"/>).
170 <link to="http://helm.cs.unibo.it/">HELM</link> directory.
171 <notice class="alpha" text="Notice: the HELM rendering engine is offline."/>