Project Contributions to Concentration Areas

(1)
Develop proof-checking and model checking for certifying proofs of the standard body of computationally related mathematics.
The PhD thesis of A. Nogin deals with this topic.
Theory and Implementation of an Efficient Tactic-Based Logical Framework.

The paper by James Caldwell and John Cowles shows how to use one prover, ACL2, to certify results in another, Nuprl.
Representing Nuprl Proof Objects in ACL2: Toward a Proof Checker for Nuprl.

MetaPRL --- A Modular Logical Environment.
This multiple-author paper describes one of the systems we use to generate content.
(2)
Catalog those principal mathematical concepts, together with their formal definitions, which are used in contemporary computing.
At present we rely on collecting the content into books and displaying them on the Web in the Nuprl Libraries and PVS Libraries. The inter-book hyperlinks provide navigation. The FDL content allows full interobject linking and is described in The FDL Navigator: Browsing and Manipulating Formal Content.
(3)
Investigate suitable base language and logic within which competing logics can be expressed and evaluated.
This paper by Robert Constable discusses the logical issues that arise in trying to relate constructive and classical theorem provers. It discusses Evan Moran's extensions of Howe's results relating Computational Type Theory (CTT) to classical ZFC set theory. It also discusses the Logic of Events.
Information-Intensive Proof Technology, by Robert Constable.

This paper by Robert Constable surveys the ideas of general type theory that underlie many theorem provers and proof development systems. The vast majority of these systems use type theory.
Naive Computational Type Theory.

This LICS 2003 paper by A. Kopylov introduces the dependent intersection type and shows how to use it to define dependent records and thus to internalize formal theories. It illustrates these ideas with abstract algebra examples. The results apply to the structure of libraries, for example showing how to internalize Automath-like contexts.
Dependent Intersection: A New Way of Defining Records in Type Theory.

This paper by Robert Constable shows how Kopylov's results apply to Automath and it also discusses results in A. Nogin's PhD thesis that improve the axiomatic basis for quotient structures in type theories. Recent Results in Type Theory and Their Relationship to Automath.
(4)
Provide automated assistance for routine aspects of developing libraries of formal theorems, proofs, algorithms, and their expressions as programs.
This paper by J. Hickey, A. Nogin, A. Granicz, and B. Aydemir shows how to structure a compiler as a sequence of program transformation algorithms that are formalized in a logical framework and stored in a formal digital library.
Formal Compiler Implementation in a Logical Framework, by Jason Hickey, et al.

The FDL Navigator: Browsing and Manipulating Formal Content by Christoph Kreitz shows how to provide basic operations of creating definitions and theorems in the FDL.
 
(5)
Investigate forms of assured interoperation for assembling, composing, specializing, and generalizing algorithmic knowledge.
The fundamental papers of Stuart Allen deal precisely with these issues.

Notes on the Design and Purpose of the FDL.

Abstract Identifiers and Textual Reference.
(6)
Investigate reflection for coordination, interoperation, and dynamic adaptation.
Reflection is critical both to content and to relating theories. The paper of PhD student Eli Barzilay with Stuart Allen is one example.
Reflecting Higher-Order Abstract Syntax in Nuprl.

The system description by Barzilay, Allen and Constable is another contribution.
Practical Reflection in Nuprl.
(7)
Study issues of consistency and maintenance among libraries.
This paper by Robert Constable gives an account of Doug Howe's result that Classical CTT is consistent (see Howe's Semantic Foundations for Embedding HOL in Nuprl).
Information-Intensive Proof Technology, by Robert Constable.

The papers of Stuart Allen cited in (5) also deal with consistency.
(8)
Address the human-computing aspects of syntaxes and concepts that are appropriate for both foundational developers and end-users.
We use two specialized editors, one for Nuprl and one for the FDL that also applies to Nuprl. We have not written articles, but the work of Lori Lorigo on the XML interface is relevant. See Latest News.
(9)
Explore innovative metaphors and protocols for understanding, using, composing, searching, authenticating, and validating constructive results.
The Master's thesis of Xin Yu deals with connecting constructive mathematics and classical.
Formalizing Abstract Algebra in Constructive Set Theory.
(10)
Examine models of applicable assurance structures and their economics.