Events and news relevant to the Laboratory for Foundations of Computer Science

[Ohad Kammar <ohad.kammar@ed.ac.uk>]

Hi,

We'll have an LFCS seminar today, a part of Nachi's modal logic theme:

  Tuesday, 05 May, 4.10pm

  Greg Restall, University of St Andrews

  The seminar will take place in-person only.

We're synchronising the seminar time with the teaching timetable, and

plan to start the talk at the advertised time, so please arrive a minute or two

earlier.

In detail:

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Greg Restall, University of St Andrews

https://consequently.org

  Tue, 05 May, 4.10pm

  Venue: IF G.03

Title: Thoroughly Linear Hypersequents

Abstract

In this talk I will introduce a simple hypersequent calculus for the

propositional modal logic S5, explaining how this representation

encodes a natural form of reasoning about possibility and necessity. I

then explain how the familiar structural rules of contraction and

weakening take two forms in such a hypersequent calculus: they operate

inside sequents, as familiar in substructural logics (linear logic,

relevant logics, affine logic, etc.), but they also take an outer form,

governing weakening or contraction of zones in a sequent. This

motivates the formulation of a thoroughly linear hypersequent modal

logic, in which we do without both inner and outer forms of contraction

and weakening. This results in a novel modal logic, with a cut-free

hypersequent calculus giving a straightforward decision procedure.

Simple models (algebras) can be used to show how the logic differs from

classical S5. These results help us understand the relationship

between operational rules and structural rules in a generalised

sequent calculus setting. The talk ends with some gestures toward open

problems and possible applications.

Bio: Greg Restall is Shelby Cullom Davis Professor of Philosophy at the

University of St Andrews, and the director of the Arché Philosophical

Research Centre for Logic, Language, Metaphysics and Epistemology.

He received his Ph.D. from the University of Queensland in 1994, and has

held positions at the Australian National University, Macquarie

University, and the University of Melbourne. His research focuses on

logic, and its connections to issues in language, epistemology and

metaphysics. He is the author of An Introduction to Substructural

Logics (Routledge, 2000), Logic (Routledge, 2006), Logical

Pluralism(Oxford University Press, 2006; with Jc Beall) and Logical

Methods (MIT Press, 2023; with Shawn Standefer). He is a Fellow of the

Australian Academy of the Humanities. His personal website is

https://consequently.org.

----------------------------------------------------------------------

Upcoming seminars:

------------------

26 May: Dominic Mulligan, Amazon Web Services, Cambridge: Nitro Isolation Engine:

        formally verifying a production hypervisor

If you would like to propose a speaker, or speak yourself, please contact me.

The seminar webpages:

http://web.inf.ed.ac.uk/lfcs/events/lfcs-seminars

Yours,

Ohad.

The University of Edinburgh is a charitable body, registered in Scotland, with registration number SC005336. Is e buidheann carthannais a th’ ann an Oilthigh Dhùn Èideann, clàraichte an Alba, àireamh clàraidh SC005336.