The Formal Systems of the λδ (\lambda\delta) Family
Computer-checked formal specifications
The systems of the λδ family are developed as machine-checked digital specifications,
and are listed in the next table, which includes the major milestones.
The life cycle of a specification consists of four periods.
Alpha:
the definitions are designed and the major propositions are proved,
then the calculus is announced with a presentation.
Beta:
major changes and additions may occur before the calculus is released on paper.
Gamma:
subsequent improvements occur until the specification is completed or superseded,
while major changes and additions are announced and reported on paper.
Delta:
after its conclusion, the specification is modified just for maintenance.
Informational pages on the specifications are provided.
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Notice on displayed numerical acounts:
nodes are counted according to the "intrinsic complexity measure"
[F. Guidi: "Procedural Representation of CIC Proof Terms"
Journal of Automated Reasoning 44(1-2), Springer (February 2010), pp. 53-78].
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Notice on displayed logical structures:
from the logical standpoint, the source scripts are grouped in "planes"
and these are grouped in "components";
the notation for the relations or functions
introduced in each script, is shown in parentheses (? are placeholders).
λδ version 3 (proposed)
The formal specification of λδ version 3
is forthcoming.
λδ version 2 (active)
The formal specification of λδ version 2
is available in the following formats:
Informational pages on the parts of the specification:
Background,
Core,
Applications.
λδ version 1 (superseded)
The formal specification of λδ version 1
is available in the following formats:
Informational pages on the parts of the specification:
Background,
Core.
Last update: Fri, 04 Mar 2016 16:15:58 +0100