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"
6 head = "The Formal Systems of the λδ (\lambda\delta) Family"
8 <sitemap name="sitemap"/>
10 <section15 name="specifications">Computer-checked formal specifications</section15>
12 The systems of the λδ family are developed as machine-checked digital specifications,
13 and are listed in the next table, which includes the major milestones.
16 The life cycle of a specification consists of four periods.
17 <notice class="alpha" text="Alpha:"/>
18 the definitions are designed and the major propositions are proved,
19 then the calculus is announced with a presentation.
20 <notice class="beta" text="Beta:"/>
21 major changes and additions may occur before the calculus is released on paper.
22 <notice class="gamma" text="Gamma:"/>
23 subsequent improvements occur until the specification is completed or superseded,
24 while major changes and additions are announced and reported on paper.
25 <notice class="delta" text="Delta:"/>
26 after its conclusion, the specification is modified just for maintenance.
28 <table name="versions"/>
31 Informational pages on the specifications are provided.
33 <topitem name="notice1">
34 <notice class="alpha" text="Notice on displayed numerical acounts:"/>
35 nodes are counted according to the "intrinsic complexity measure"
36 [F. Guidi: "Procedural Representation of CIC Proof Terms"
37 Journal of Automated Reasoning 44(1-2), Springer (February 2010), pp. 53-78].
39 <topitem name="notice2">
40 <notice class="alpha" text="Notice on displayed logical structures:"/>
41 from the logical standpoint, the source scripts are grouped in "planes"
42 and these are grouped in "components";
43 the notation for the relations or functions
44 introduced in each script, is shown in parentheses (? are placeholders).
47 <!-- VERSION 2 =========================================================== -->
49 <subsection name="v2"><version2-icon/>λδ version 2 (active)</subsection>
51 The formal specification of λδ version 2
52 is available in the following formats:
55 <topitem name="source2">
57 <rlink to="download/lambdadelta_2A1.tar.gz">lambdadelta_2A1 for Matita 0.99.2</rlink>
58 (revised <notice class="gamma" text="2014-10"/>).
60 <rlink to="documentation.html#ldR2c">Documentation (R2c)</rlink>.
63 The scripts are grouped in directories, first by part, then by component.
66 <notice class="alpha" text="Notice:"/>
67 the scripts are checked by the latest version of Matita from
68 <link to="http://matita.cs.unibo.it/download.shtml">HELM Subversion repository</link>
69 at path <trunk/matita/>.
74 Informational pages on the parts of the specification:
75 <rlink to="ground_2.html">Background</rlink>,
76 <rlink to="basic_2.html">Core</rlink>,
77 <rlink to="apps_2.html">Applications</rlink>.
80 <!-- VERSION 1 =========================================================== -->
82 <subsection name="v1"><version1-icon/>λδ version 1 (superseded)</subsection>
84 The formal specification of λδ version 1
85 is available in the following formats:
88 <topitem name="source1">
90 <rlink to="download/lambdadelta_1.tar.gz">lambdadelta_1 for Coq 7.3.1</rlink>
91 (revised <notice class="delta" text="2015-09"/>).
93 <rlink to="documentation.html#ldJ1a">Documentation (J1a)</rlink>.
95 <notice class="delta" text="2015 January 15."/>
96 17 new lemmas and former lemma "eq_nat_dec" renamed as "nat_dec_neg".
100 The scripts are grouped in directories, one for each part.
104 <topitem name="static1">
105 <rlink to="static/matita/lambdadelta/">lambdadelta_1 for Matita 0.5</rlink>
106 (revised <notice class="delta" text="2011-09"/>).
107 Static HTML pages generated by the <link to="http://helm.cs.unibo.it/">HELM</link> rendering engine.
109 <rlink to="static/matita/lambdadelta/basic_1/pr3/pr3/pr3_confluence.con.html">
110 Confluence of reduction</rlink>
111 (Church-Rosser property).
113 <rlink to="static/matita/lambdadelta/basic_1/ty3/props/ty3_correct.con.html">
114 Correctness of types</rlink>.
116 <rlink to="static/matita/lambdadelta/basic_1/ty3/props/ty3_unique.con.html">
117 Uniqueness of types up to conversion</rlink>.
119 <rlink to="static/matita/lambdadelta/basic_1/ty3/pr3/ty3_sred_pr3.con.html">
120 Subject reduction of the type assignment</rlink>.
122 <rlink to="static/matita/lambdadelta/basic_1/ty3/arity_props/ty3_sn3.con.html">
123 Strong normalization of the typed terms</rlink>.
125 <rlink to="static/matita/lambdadelta/basic_1/ty3/dec/ty3_inference.con.html">
126 Decidability of the type inference problem</rlink>.
130 <topitem name="dynamic1">
131 <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/">
132 lambdadelta_1 for Matita 0.5</link>
133 (revised <notice class="delta" text="2011-09"/>).
134 <link to="http://helm.cs.unibo.it/">HELM</link> directory.
135 <notice class="alpha" text="Notice: the HELM rendering engine is offline."/>
139 Informational pages on the parts of the specification:
140 <rlink to="ground_1.html">Background</rlink>,
141 <rlink to="basic_1.html">Core</rlink>.