894 research outputs found
A Comparative Study of Coq and HOL
This paper illustrates the differences between the style of theory mechanisation of Coq and of HOL. This comparative study is based on the mechanisation of fragments of the theory of computation in these systems. Examples from these implementations are given to support some of the arguments discussed in this paper. The mechanisms for specifying definitions and for theorem proving are discussed separately, building in parallel two pictures of the different approaches of mechanisation given by these systems
A Proof of the S-m-n theorem in Coq
This report describes the implementation of a mechanisation of the theory of computation in the Coq proof assistant which leads to a proof of the Smn theorem. This mechanisation is based on a model of computation similar to the partial recursive function model and includes the definition of a computable function, proofs of the computability of a number of functions and the definition of an effective coding from the set of partial recursive functions to natural numbers. This work forms part of a comparative study of the HOL and Coq proof assistants
A Vernacular for Coherent Logic
We propose a simple, yet expressive proof representation from which proofs
for different proof assistants can easily be generated. The representation uses
only a few inference rules and is based on a frag- ment of first-order logic
called coherent logic. Coherent logic has been recognized by a number of
researchers as a suitable logic for many ev- eryday mathematical developments.
The proposed proof representation is accompanied by a corresponding XML format
and by a suite of XSL transformations for generating formal proofs for
Isabelle/Isar and Coq, as well as proofs expressed in a natural language form
(formatted in LATEX or in HTML). Also, our automated theorem prover for
coherent logic exports proofs in the proposed XML format. All tools are
publicly available, along with a set of sample theorems.Comment: CICM 2014 - Conferences on Intelligent Computer Mathematics (2014
Proving soundness of combinatorial Vickrey auctions and generating verified executable code
Using mechanised reasoning we prove that combinatorial Vickrey auctions are
soundly specified in that they associate a unique outcome (allocation and
transfers) to any valid input (bids). Having done so, we auto-generate verified
executable code from the formally defined auction. This removes a source of
error in implementing the auction design. We intend to use formal methods to
verify new auction designs. Here, our contribution is to introduce and
demonstrate the use of formal methods for auction verification in the familiar
setting of a well-known auction
Set Theory or Higher Order Logic to Represent Auction Concepts in Isabelle?
When faced with the question of how to represent properties in a formal proof
system any user has to make design decisions. We have proved three of the
theorems from Maskin's 2004 survey article on Auction Theory using the
Isabelle/HOL system, and we have produced verified code for combinatorial
Vickrey auctions. A fundamental question in this was how to represent some
basic concepts: since set theory is available inside Isabelle/HOL, when
introducing new definitions there is often the issue of balancing the amount of
set-theoretical objects and of objects expressed using entities which are more
typical of higher order logic such as functions or lists. Likewise, a user has
often to answer the question whether to use a constructive or a
non-constructive definition. Such decisions have consequences for the proof
development and the usability of the formalization. For instance, sets are
usually closer to the representation that economists would use and recognize,
while the other objects are closer to the extraction of computational content.
In this paper we give examples of the advantages and disadvantages for these
approaches and their relationships. In addition, we present the corresponding
Isabelle library of definitions and theorems, most prominently those dealing
with relations and quotients.Comment: Preprint of a paper accepted for the forthcoming CICM 2014 conference
(cicm-conference.org/2014): S.M. Watt et al. (Eds.): CICM 2014, LNAI 8543,
Springer International Publishing Switzerland 2014. 16 pages, 1 figur
Applying Formal Methods to Networking: Theory, Techniques and Applications
Despite its great importance, modern network infrastructure is remarkable for
the lack of rigor in its engineering. The Internet which began as a research
experiment was never designed to handle the users and applications it hosts
today. The lack of formalization of the Internet architecture meant limited
abstractions and modularity, especially for the control and management planes,
thus requiring for every new need a new protocol built from scratch. This led
to an unwieldy ossified Internet architecture resistant to any attempts at
formal verification, and an Internet culture where expediency and pragmatism
are favored over formal correctness. Fortunately, recent work in the space of
clean slate Internet design---especially, the software defined networking (SDN)
paradigm---offers the Internet community another chance to develop the right
kind of architecture and abstractions. This has also led to a great resurgence
in interest of applying formal methods to specification, verification, and
synthesis of networking protocols and applications. In this paper, we present a
self-contained tutorial of the formidable amount of work that has been done in
formal methods, and present a survey of its applications to networking.Comment: 30 pages, submitted to IEEE Communications Surveys and Tutorial
Tableaux Modulo Theories Using Superdeduction
We propose a method that allows us to develop tableaux modulo theories using
the principles of superdeduction, among which the theory is used to enrich the
deduction system with new deduction rules. This method is presented in the
framework of the Zenon automated theorem prover, and is applied to the set
theory of the B method. This allows us to provide another prover to Atelier B,
which can be used to verify B proof rules in particular. We also propose some
benchmarks, in which this prover is able to automatically verify a part of the
rules coming from the database maintained by Siemens IC-MOL. Finally, we
describe another extension of Zenon with superdeduction, which is able to deal
with any first order theory, and provide a benchmark coming from the TPTP
library, which contains a large set of first order problems.Comment: arXiv admin note: substantial text overlap with arXiv:1501.0117
ProofBuddy: A Proof Assistant for Learning and Monitoring
Proof competence, i.e. the ability to write and check (mathematical) proofs,
is an important skill in Computer Science, but for many students it represents
a difficult challenge. The main issues are the correct use of formal language
and the ascertainment of whether proofs, especially the students' own, are
complete and correct. Many authors have suggested using proof assistants to
assist in teaching proof competence, but the efficacy of the approach is
unclear. To improve the state of affairs, we introduce ProofBuddy: a web-based
tool using the Isabelle proof assistant which enables researchers to conduct
studies of the efficacy of approaches to using proof assistants in education by
collecting fine-grained data about the way students interact with proof
assistants. We have performed a preliminary usability study of ProofBuddy at
the Technical University of Denmark.Comment: In Proceedings TFPIE 2023, arXiv:2308.0611
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