Supergroup BLAST!
Shay Logan
Supergroup announcement time! This week Johannes Stern speaks in the Foundational Studies Bristol series, Marcelo Finger speaks in the Lógicos em Quarentena Series hosted by the Brazilian Logic Society, and Roy Cook will speak in the Supergroup series. Details below.
Also important: the 24 hours of inclusive logic happened and was *awesome*. Stay tuned as we process, update, edit, improve and continue the work begun there!
Speaker: Roy T. Cook
Title: On the Expressive Completeness of Minecraft
Time and Date: Thursday June 18, 8pm GMT-5
Password: 038519
Abstract: Redstone is a system of components in the Minecraft video game that allows players to build various virtual machines. If we merely consider whether a redstone circuit is powered or not, then redstone circuitry is both functionally complete with respect to classical propositional functions (since it is easy to build, e.g., a NOR gate) and Turing complete (in the slightly attenuated practical sense, often mobilized in computer science discussions, that ignores the finitude of the memory in any particular machine). Much has been made of this as a means to teach basic propositional logic, and ambitious minecraft players have built fully functional (finite memory) universal Turing machines within the game. The Minecraft redstone circuitry system is, however, far more complex than this. Circuits are not merely on or off, powered or unpowered. Instead, the voltage running through a redstone circuit varies from level 0 (unpowered) to level 15 (fully powered). Hence, redstone circuitry involves a sixteen-valued logic. In this talk I will prove that the available redstone components in Minecraft are functionally complete with respect to sixteen-valued truth functions, and in fact are redundant - not all available components are required for the proof. Along the way we will also see some interesting examples of the kinds of computing machines that can be built within Minecraft, including a sixteen-valued memory circuit.
Talks by Member Groups
Foundational Studies Bristol
Speaker: Johannes Stern (Bristol)
Title: Belief, Truth, and Ways of Believing
Time and Date: Tuesday, June 16, 9am GMT-5
Abstract: The notions of belief and truth frequently interact in philosophical discourse but, surprisingly, a coherent semantics for such discourse is still wanting. Indeed, a number of puzzles stand in way of a satisfactory semantic account of the notion of truth in doxastic and epistemic contexts. In this talk I will discuss these puzzles and then sketch a semantic account that combines ideas from contextualist theories of attitude reports and Awareness semantics for non-idealized belief.
Lógicos em Quarentena (Brazilian Logic Society)
Speaker: Marcelo Finger
Title: Logic and Numbers
Time and Date: Wednesday, June 17, 6pm GMT-5
Abstract: We present a research program which investigates the intersection of deductive reasoning with explicit quantitative capabilities. These capabilities encompass probabilistic reasoning, counting and counting quantifiers, and similar systems. The need to have a combined reasoning system that enables a unified way of reasoning with quantities has always been recognized in modern logic, as proposals of probabilistic logic reasoning are present since the work of Boole [1854]. Equally ubiquitous is the need to deal with cardinality restrictions on finite sets. More recently, a well-founded probabilistic theory has been developed for non-classical settings as well, such as probabilistic reasoning over Lukasiewicz infinitely-valued logic.
We show that there is a common way to deal with these several deductive quantitative capabilities, involving a framework based on Linear Algebra and Linear Programming. The distinction between classical and non-classical reasoning on the one hand, and probabilistic and cardinality reasoning on the other hand, comes from the different family of algebras employed. The quantitative logic systems also allow for the introduction of inconsistency measurements, which quantify the degree of inconsistency of a given quantitative logic theory, following some basic principles of inconsistency measurements.
On the computational level, we aim at exploring quantitative logic systems in which the complexity of reasoning is "only NP-complete". We provide open-source implementations for solvers operating over those systems and study some notable empirical properties, such as the presence of a phase transition.
Other Notes and Announcements:
- Walter Dean (Warwick) is giving a talk at the Aristotelian Society that some supergroup members might be interested in. More details are available here: https://www.aristoteliansociety.org.uk/the-proceedings/the-2019-20-programme/walter-dean/?mc_cid=167a20ee4f&mc_eid=380a4e9011
- The Web School on Logic, Language, and Information is happening July 11-19. More information at https://www.brandeis.edu/nasslli2020/. Of particular interest to our members might be the workshop called Natural Logic Meets Machine Learning; more info at https://typo.uni-konstanz.de/naloma20/.
- To access the supergroup calendar, please follow this link: https://calendar.google.com/calendar?cid=ZGhoanNoanF1bGhmaG9xam5scDJlc2o0bDhAZ3JvdXAuY2FsZW5kYXIuZ29vZ2xlLmNvbQ
- To access the member groups joint calendar, please follow this link: https://calendar.google.com/calendar?cid=aG8wNWljaGxkNXI2N2oyMnZvY3BzdmRoMWNAZ3JvdXAuY2FsZW5kYXIuZ29vZ2xlLmNvbQ
- If you represent a member group and would like your events to appear on the joint calendar, be sure to add them! Contact me if you need permission to do so.
Yay for logic!
Shay
Shay Logan
Supergroup Talk:
Speaker: Valeria de Paiva (Topos Institute)
Title: Dialectica categories for the Lambek calculus
Time and Date: Thursday, June 25, 8pm GMT-5
Link: https://unimelb.zoom.us/j/846890369?pwd=TktZYmlIUGlYOU9ZaXFJcCt0TFJFZz09.
Abstract: Dialectica categorical models of the Lambek Calculus were first presented in the Amsterdam Colloquium a long time ago. Following Lambek's lead, we approached the Lambek Calculus from the perspective of Linear Logic and adapted the Dialectica categorical models for Linear Logic to Lambek's non-commutative calculus. The old work took for granted the syntax of the Lambek calculus and only discussed the exciting possibilities of new models for the modalities that Linear Logic introduced. Many years later we find that the work on dialectica models of the Lambek calculus is still interesting and that it might inform some of the most recent work on the relationship between Categorial Grammars and notions of Distributional Semantics.
Thus we revisited the old work, making sure that the syntax details that were sketchy on the first version got completed and verified, using automated tools such as Agda and Ott. Ultimately we are interested in the applicability of the original systems to their intended uses in the construction of semantics of Natural Language. But before we can discuss it, we need to make sure that the mathematical properties that make the Lambek calculus attractive are all properly modeled and this is the main aim of this paper.
We recall the Lambek calculus with its Curry-Howard isomorphic term assignment system. We extend it with a $\kappa$ modality, inspired by Yetter's work, which makes the calculus commutative. Then we add the of-course modality $!$, as Girard did, re-introducing weakening and contraction for all formulas and get back the full power of intuitionistic and classical logic. We also present algebraic semantics and categorical semantics, proved sound and complete for the whole system. Finally, we show the traditional properties of type systems, like subject reduction, the Church-Rosser theorem and normalization for the calculi of extended modalities, which we did not have before.
Speaker: Pilar Terrés (Barcelona)Title: The different senses of ‘and’: a pragmatic solution to Free Choice and Preface ParadoxesTime and Date: Tuesday June 23, 10am GMT-5Abstract: In this talk, I aim to explore the behaviour of conjunction under the scope of certain modal operator (such as possibility or permission). I argue that in certain modal contexts, classical logic fails to capture the behaviour of “and”, giving rise to certain paradoxes (such as the lottery, the preface and the free choice paradoxes), and that a logic without contraction can better formalize it (following and reinterpreting the work of Paoli, Zardini and Barker). Moreover, I argue that this deviation in the behaviour of conjunction can be explained pragmatically.
Other Notes and Announcements:
- The Web School on Logic, Language, and Information is happening July 11-19. More information at https://www.brandeis.edu/nasslli2020/. Of particular interest to our members might be the workshop called Natural Logic Meets Machine Learning; more info at https://typo.uni-konstanz.de/naloma20/.
- To access the supergroup calendar, please follow this link: https://calendar.google.com/calendar?cid=ZGhoanNoanF1bGhmaG9xam5scDJlc2o0bDhAZ3JvdXAuY2FsZW5kYXIuZ29vZ2xlLmNvbQ
- To access the member groups joint calendar, please follow this link: https://calendar.google.com/calendar?cid=aG8wNWljaGxkNXI2N2oyMnZvY3BzdmRoMWNAZ3JvdXAuY2FsZW5kYXIuZ29vZ2xlLmNvbQ
- If you represent a member group and would like your events to appear on the joint calendar, be sure to add them! Contact me if you need permission to do so.
Yay for logic!
Damian Szmuc
Dear Cheerful Logicians and Friends of Logic,
Supergroup announcement time! Brief Summary: On Wednesday, Ekaterina Kubyshkina will give a talk about a truth-functional perspective on ignorance. On Thursday, Gilles Dowek will give a talk on a Wikipedia of formal proofs. Also on Thursday, João Marcos will give this week's talk at the Logic Supergroup on gaps and gluts. Details below.
Supergroup Talk:
Speaker: João Marcos (DIMAp / CCET / UFRN)
Title: Let gluts and gaps prevail!
Time and Date: Thursday, July 2, 8pm GMT-5
Link: https://ksu.zoom.us/j/7613620942
Password: Gaps&Gluts
Abstract: One of the all time favorite strategies for defining a non-classical negation proceeds by considering additional truth-values, besides `the True' and `the False', with the intent of using the latter to localise the phenomena of negation-inconsistency and negation-undeterminedness. From a philosophical standpoint, such an approach often translates, with varying degrees of success, into the consideration of `gaps' and `gluts', thought of as truth-values on their own right. From the perspective of the standard Tarskian consequence-theoretic framework, one may claim that the collection of truth-values associated to a given logic constitutes hardly anything beyond a technical expedient used within the so-called `logical matrices' in order to define some convenient notion of entailment. Indeed, at the metalogical level, no more than one or two `logical values' are needed in order to explicate any given consequence relation and the associated one-dimensional `logical theories' that are intended to collect the assertions upon which one happens to be interested. In this talk I will defend the systematic use of a generalized notion of logical consequence that allows for: (i) gappy and glutty reasoning to be naturally captured, at the metalogical level; (ii) a two-dimensional notion of logical theory, containing both assertions and denials, to be explored; (iii) a plurality of inferential mechanisms to cohabit. Furthermore, concerning the choice of logical primitives, I will also argue that truth-values and judgments about logical consequence are advantageously replaced by cognitive attitudes and judgments about logical incompatibility.
Talks by Member Groups:
Colloquium Logicae (CLE-UNICAMP)
Speaker: Ekaterina Kubyshkina (CLE-UNICAMP)
Title: Ignorance: A Truth-Functional Perspective
Time and Date: Wednesday, July 1, 2 pm GMT-3
Link: https://conferenciaweb.rnp.br/spaces/unicamp-cle-colloquium-logicae
Abstract: I will present a family of four-valued logics, dubbed logics of rational agent, where the epistemic state of an agent is represented truth-functionally. In particular, these logics permit one to formalize the fact of being ignorant of or knowing some truth at the level of valuations, without the explicit use of epistemic operators. On the basis of this semantics several sound and complete systems will be provided. Moreover, these systems, extended by alethic modalities of necessity and possibility, will be applied to the analysis of an epistemological problem known as knowability paradox, or Church-Fitch paradox.
Lógicos em Quarentena (SBL)
Speaker: Gilles Dowek (LSV, CNRS & ENS Paris-Saclay)
Title: Logipedia: towards a Wikipedia of formal proofs
Time and Date: Thursday, July 2, 4 pm GMT-3
Link: https://meet.google.com/bcn-yfqx-ruz
Abstract: Formal computerized proofs are now a central tool in computer science and in mathematics. But, each system – Coq, HOL Light, Isabelle/HOL, PVS... – implements its own language and its own theory, limiting the interoperability between systems and the sustainability of these proofs. Logipedia is an, in progress, encyclopedia of formal proofs, expressed in various theories. It is based on the idea to express these theories in a new logical framework allowing bound variables, explicit proof-terms, computation rules, and peaceful co-existence of constructive and non constructive proofs.
Other Notes and Announcements:
The Web School on Logic, Language, and Information is happening July 11-19. More information at https://www.brandeis.edu/nasslli2020/. Of particular interest to our members might be the workshop called Natural Logic Meets Machine Learning; more info at https://typo.uni-konstanz.de/naloma20/.
To access the supergroup calendar, please follow this link: https://calendar.google.com/calendar?cid=ZGhoanNoanF1bGhmaG9xam5scDJlc2o0bDhAZ3JvdXAuY2FsZW5kYXIuZ29vZ2xlLmNvbQ
To access the member groups joint calendar, please follow this link: https://calendar.google.com/calendar?cid=aG8wNWljaGxkNXI2N2oyMnZvY3BzdmRoMWNAZ3JvdXAuY2FsZW5kYXIuZ29vZ2xlLmNvbQ
If you represent a member group and would like your events to appear on the joint calendar, be sure to add them! Contact me if you need permission to do so.
Yay for logic!
Damian Szmuc
IIF-SADAF-CONICET and University of Buenos Aires, Argentina
https://sites.google.com/view/damianszmuc
Joao Marcos
> Title: Let gluts and gaps prevail!
> Time and Date: Thursday, July 2, 8pm GMT-5
10 horas da noite.
https://www.thetimezoneconverter.com/
Pijamas são permitidos --- só que não!
[]s,
Joao Marcos
Marcelo Finger
--
Você está recebendo esta mensagem porque se inscreveu no grupo "LOGICA-L" dos Grupos do Google.
Para cancelar inscrição nesse grupo e parar de receber e-mails dele, envie um e-mail para logica-l+u...@dimap.ufrn.br.
Para ver esta discussão na web, acesse https://groups.google.com/a/dimap.ufrn.br/d/msgid/logica-l/CAO6j_Li0g_RYGwGHa2g%2B0X7tWegr7gogfZ7EjYOSNiEwLgQZpw%40mail.gmail.com.
Departament of Computer Science, IME
University of Sao Paulo
http://www.ime.usp.br/~mfinger
ResearcherID: A-4670-2009
Joao Marcos
Antes "pedante" do que "pedinte", haha...
> 2. Pijama de bolinha vale?
palestra): \circ e \bullet!
[]s, JM
--
http://sequiturquodlibet.googlepages.com/
Marcelo Finger
Joao Marcos
prevail!" foi registrada:
https://youtu.be/CBBu4HBPOxE
Aproveito para agradecer por todo o feedback recebido, e para
apresentar minhas desculpas pessoais àqueles que se perderam entre as
duas salas em que aparentemente se supunha que eu devesse estar ao
mesmo tempo. :-x
Joao Marcos
> Supergroup Talk:
>
> Speaker: João Marcos (DIMAp / CCET / UFRN)
> Title: Let gluts and gaps prevail!
> Time and Date: Thursday, July 2, 8pm GMT-5
> Link: https://ksu.zoom.us/j/7613620942
> Password: Gaps&Gluts
>
> Abstract: One of the all time favorite strategies for defining a non-classical negation proceeds by considering additional truth-values, besides `the True' and `the False', with the intent of using the latter to localise the phenomena of negation-inconsistency and negation-undeterminedness. From a philosophical standpoint, such an approach often translates, with varying degrees of success, into the consideration of `gaps' and `gluts', thought of as truth-values on their own right. From the perspective of the standard Tarskian consequence-theoretic framework, one may claim that the collection of truth-values associated to a given logic constitutes hardly anything beyond a technical expedient used within the so-called `logical matrices' in order to define some convenient notion of entailment. Indeed, at the metalogical level, no more than one or two `logical values' are needed in order to explicate any given consequence relation and the associated one-dimensional `logical theories' that are intended to collect the assertions upon which one happens to be interested. In this talk I will defend the systematic use of a generalized notion of logical consequence that allows for: (i) gappy and glutty reasoning to be naturally captured, at the metalogical level; (ii) a two-dimensional notion of logical theory, containing both assertions and denials, to be explored; (iii) a plurality of inferential mechanisms to cohabit. Furthermore, concerning the choice of logical primitives, I will also argue that truth-values and judgments about logical consequence are advantageously replaced by cognitive attitudes and judgments about logical incompatibility.
http://sequiturquodlibet.googlepages.com/
Damian Szmuc
Dear Cheerful Logicians and Friends of Logic,
Supergroup announcement time! Brief Summary: On Thursday, Johanna Franklin will give a talk on randomness and computability theory. Also on Thursday, Shawn Standefer will give this week's talk at the Logic Supergroup on semantics for relevant logics. Details below.
Supergroup Talk:
Speaker: Shawn Standefer (Melbourne)
Title: Functionality and Reflexivity: Adventures in Collection Frame Theory
Time and Date: Thursday, July 9, 8 pm GMT-5
Link: https://unimelb.zoom.us/j/846890369?pwd=TktZYmlIUGlYOU9ZaXFJcCt0TFJFZz09
Abstract: In this talk I will discuss some features of special classes of collection frames for relevant logics. In particular, I will discuss functional set frames and their connection to Urquhart's semilattice semantics, and I will discuss non-reflexive collection frames and some of the consequences of dropping the reflexivity requirement. This is partially joint work with Greg Restall.
Talks by Member Groups:
Lógicos em Quarentena (SBL)
Speaker: Johanna Franklin (Hofstra University)
Title: Randomness and computability theory
Time and Date: Thursday, July 9, 4 pm GMT-3
Link: http://meet.google.com/jnd-aopk-efq
Abstract: Computability theory provides us with a framework for formalizing our intuitions about randomness. In this talk, I will discuss different ways in which this is done and present some tests to determine whether a particular formalization seems reasonable.
Other Notes and Announcements:
The Logic Supergroup has a YouTube channel! Recordings of almost all talks are available at https://www.youtube.com/channel/UCqOAS8SHP-5nGjYEE2FE6xw
The Web School on Logic, Language, and Information is happening July 11-19. More information at https://www.brandeis.edu/nasslli2020/. Of particular interest to our members might be the workshop called Natural Logic Meets Machine Learning; more info at https://typo.uni-konstanz.de/naloma20/.
To access the supergroup calendar, please follow this link: https://calendar.google.com/calendar?cid=ZGhoanNoanF1bGhmaG9xam5scDJlc2o0bDhAZ3JvdXAuY2FsZW5kYXIuZ29vZ2xlLmNvbQ
To access the member groups joint calendar, please follow this link: https://calendar.google.com/calendar?cid=aG8wNWljaGxkNXI2N2oyMnZvY3BzdmRoMWNAZ3JvdXAuY2FsZW5kYXIuZ29vZ2xlLmNvbQ
If you represent a member group and would like your events to appear on the joint calendar, be sure to add them! Contact any of the organizers if you need permission to do so.
Yay for logic!
Stay safe,
Damian Szmuc
