Main.Events History
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- 3o. Encontro Brasileiro de Mulheres na Matemática (EBMM). SBL awarded student grants to: Jeanne Albuquerque (UFPA) and Débora Rodrigues (PUC-Rio)
- Semana Temática de Lógica, Topologia e Teoria de Conjuntos IME - UFBA. SBL will award 02 student grants. Click here to know the details.
- Semana Temática de Lógica, Topologia e Teoria de Conjuntos IME - UFBA. SBL awarded 02 student grants. Click here to know the details.
- V Workshop Brasileiro de Lógica
- V Workshop Brasileiro de Lógica
- VIII Conferência da Sociedade Brasileira de Filosofia Analítica. SBL awarded student grants to: Paola Cristina de Freitas Villa (UFSC), Jéssica Gonçalves Rodrigues (UFMA) and Jéssica Caren da Silva Melo (UFRN)
- VIII Conferência da Sociedade Brasileira de Filosofia Analítica. SBL awarded student grants to: Paola Cristina de Freitas Villa (UFSC) and Jéssica Caren da Silva Melo (UFRN)
- VIII Conferência da Sociedade Brasileira de Filosofia Analítica. SBL awarded 03 student grants to: Paola Cristina de Freitas Villa (UFSC), Jéssica Gonçalves Rodrigues (UFMA) and Jéssica Caren da Silva Melo (UFRN)
- VIII Conferência da Sociedade Brasileira de Filosofia Analítica. SBL awarded student grants to: Paola Cristina de Freitas Villa (UFSC), Jéssica Gonçalves Rodrigues (UFMA) and Jéssica Caren da Silva Melo (UFRN)
- VIII Conferência da Sociedade Brasileira de Filosofia Analítica. SBL awarded 03 student grants to: Paola Cristina de Freitas Villa (UFSC), Jéssica Gonçalves Rodrigues (UFMA) and Jéssica Caren da Silva Melo (UFRN)
2024
- Semana Temática de Lógica, Topologia e Teoria de Conjuntos IME - UFBA. SBL will award 02 student grants. Click here to know the details.
- V Workshop Brasileiro de Lógica
- WoLLIC 2024
- IV Workshop Brasileiro de Lógica
- II Workshop Brasileiro de Lógica
- III Workshop Brasileiro de Lógica
- II Workshop Brasileiro de Lógica
- Workshop on Logic, Language, Information and Computation
- Workshop on Logic, Language, Information and Computation (WoLLIC22)
- https://www.mathstat.dal.ca/wollic2023/WoLLIC 2023
- WoLLIC 2023
- https://www.mathstat.dal.ca/wollic2023/WoLLIC 2023
- II Encontro Brasileiro em Teoria das Categorias
- II Encontro Brasileiro em Teoria das Categorias
- II Encontro Brasileiro em Teoria das Categorias
- São Paulo School in Advanced Science on Contemporary Logic, Rationality, and Information
- Workshop Brasileiro de Lógica
- II Workshop Brasileiro de Lógica
- Workshop Brasileiro de Lógica
- I Workshop Brasileiro de Lógica
- Sao Paulo School of Advanced Science on Contemporary Logic, Rationality and Information
- I Dia Carol Blasio por Diversidade na Lógica
- Workshop Brasileiro de Lógica
- Reunião Anual da SBPC
- Escola Brasileira de Lógica (XX EBL)
- LSFA 2022
- Encontro Brasileiro de Lógica (XX EBL)
- Workshop Brasileiro de Lógica
- Reunião Anual da SBPC
- I Dia Carol Blasio por Diversidade na Lógica
- Logic4Peace: fundraising online Logic event for Peace
- Reunião Anual da SBPC
- Falando em Lógica...
- Logic4Peace: fundraising online Logic event for Peace
- Brazilian Logic Conference
- Workshop Brasileiro de Lógica
- Escola Brasileira de Lógica (XX EBL)
- WoLLIC 2022
- I ENC(UE-O)NTRO DE LÓGICA BRASIL-COL(O-Ô)MBIA
- I ENC(UE-O)NTRO DE LÓGICA BRASIL-COL(O-Ô)MBIA
- 16TH Logical and Semantic Frameworks with Applications LSFA 2021
Eventos apoiados pela SBL
Events supported by SBL
Events supported by SBL
Eventos apoiados pela SBL
2020
2021
- Lógica e Representatividade
- Logical and Semantic Frameworks with Applications
- Workshop Brasileiro de Lógica
2020
- The Logic Supergroup
- Lógicos em Quarentena
- Logical and Semantic Frameworks with Applications
- Workshop Brasileiro de Lógica
- São Paulo School in Advanced Science on Contemporary Logic, Rationality, and Information
- XVIIth Congress on Logic, Methodology, and Philosophy of Science and Technology
- XVII Congress on Logic, Methodology, and Philosophy of Science and Technology
- Logical and Semantic Frameworks with Applications
- Workshop Brasileiro de Lógica
- Speaking the Unspeakable: Paradoxes between Truth and Proof
2023
- XVIIth Congress on Logic, Methodology, and Philosophy of Science and Technology
- Semana Temática de Lógica, Conjuntos e Topologia
- 1st World Congress of the Brazilian Academy of Philosophy in Honor of Newton da Costa 90th Birthday
2020
- Workshop on Logic, Language, Information and Computation
- Logic and Semantic Frameworks, with Applications
- Workshop on Logical and Semantic Frameworks with Applications
- Workshop on Logical and Semantic Frameworks, with Applications
- I Simpósio de Lógica e Filosofia Analítica & VIII Conferência de Epistemologia Social
- I Symposium on Logic and Analytic Philosophy & VIII Social Epistemology Conference
- I Simpósio de Lógica e Filosofia Analítica & VIII Conferência de Epistemologia Social
- Brazilian Logic Conference
- Brazilian Logic Conference
2019
- Brazilian Logic Conference
- EBL
- Brazilian Logic Conference
- Workshop on Logical and Semantic Frameworks with Applications
- Conference on Mathematical Logic 2018
- Workshop da Sociedade Brasileira de Lógica 2017
- Conference on Mathematical Logic
- Workshop da Sociedade Brasileira de Lógica
- Conference on Mathematical Logic 2018
- Workshop da Sociedade Brasileira de Lógica 2017
- Conference on Mathematical Logic
- Workshop da Sociedade Brasileira de Lógica
Workshop da Sociedade Brasileira de Lógica
Informações importantes
- Local: Auditório do Instituto de Matemática e Estatística, UFBA (Salvador-BA)
- Data: 24 de Outubro de 2017, 14:00h
Sobre o evento
O Workshop da Sociedade Brasileira de Lógica é uma iniciativa da Sociedade Brasileira de Lógica (SBL), consistindo de palestras e comunicações convidadas, com o objetivo de apresentar um painel da pesquisa em Lógica no Brasil (e em particular no Nordeste), em todas as suas vertentes: Filosofia, Ciência da Computação, Matemática.
Os keynote speakers do Workshop são: Cezar Mortari (UFSC, atual Presidente da SBL), Walter Carnielli (UNICAMP) e Maximo Dickmann (Paris 7).
O Workshop realizar-se-á no Auditório do Instituto de Matemática e Estatística da UFBA, na mesma semana em que ocorrem em Salvador outros dois eventos relacionados à Lógica (e organizados pelo Prof. Abel Lassale Casanave, do Departamento de Filosofia da UFBA):
- o Colóquio Conesul (do Grupo Conesul de Filosofia das Ciências Formais), de 20 a 23 de Outubro, com programação já disponibilizada em http://gcfcf.com.br/pt/coloquios/
- e também o Fourth Meeting APMP (Association for the Philosophy of Mathematical Practice), de 23 a 26 de Outubro, com programação já disponibilizada em http://www.philmathpractice.org/
O Workshop é isento de inscrição. Todos os interessados em participar do Fourth Meeting APMP como ouvintes são solicitados a confirmar sua participação preenchendo a Registration Form e pagando a taxa de inscrição (R$ 150,00) até 30 de setembro. A inscrição no Meeting também permite participação no Colóquio Conesul.
Programação
Horário | Palestrante | Título |
14:00h-14:40h | Cezar Mortari (UFSC, atual presidente da SBL) | TBA |
14:50h-15:30h | Walter Carnielli (CLE/UNICAMP) | The principle of the Ariadne and the Axiom of choice |
15:35h-16:00h | Carlos Brito (UFC) | Talking about Meaning: an algorithmic approach to semantics |
16:05h-16:30h | Francicleber M. Ferreira (UFC) | Complexity of bounded-degree fixed-points |
16:30h-17:00h | Coffee break | |
17:00h-17:25h | Darllan C. Pinto (UFBA) | Congruential filter pairs and their relation with Leibniz operator |
17:30h-17:55h | Abílio A. Rodrigues Filho (UFMG) | TBA |
18:00h-18:25h | Samir Gorsky (UFRN) | Logic, epistemology and information |
18:30h-19:10h | Maximo Dickmann (Paris 7) | TBA |
Resumos das palestras
The principle of the Ariadne and the Axiom of choice (Walter Carnielli)
I intend to survey some results on combinatorial aspects of infinite Ramsey-type problems inspired by finite properties, discussing the relevance of an alternative set-theoretical principle, the so-called “Principle of Ariadne”. This principle, a rival of the Axiom of Choice and connected to the polarized partition relations, can be consistently added to the usual axiomatic stock of ZF set theory under certain conditions. The new axiom, which preserves all the finite contents of mathematics but deviates from the standard in the infinite contents, may help us to understand the finite-infinite divide in mathematics, making clear that there is more than one way to generalize from finite principles of order (or choice) to the infinite.
This is joint work with Carlos di Prisco.
Talking about Meaning: an algorithmic approach to semantics (Carlos Brito)
The terms in the natural language are typically used to designate objects in the world. However, an important characteristic of natural languages is precisely the fact that they are capable of speaking not only of the objects in the world, but also of language itself, as well as the speakers of the language. The starting point for the development of our proposed notion of algorithmic semantics is the observation that it doesn’t make sense, in some cases, to understand any term as a name for the corresponding sentence or proposition that would exist in the domain of objects. Such terms do not refer to an object, but are themselves the objects which are being talked about. Next, we observe that linguistic objects do not have the same nature as the objects of the world: their properties are not assessed through perceptual inspection, but are defined by the conventional rules of the language. These two observations give rise to the idea of a semantic value that is produced by the execution of an algorithm which verifies a set of rules. The notion of algorithmic semantics opens the way to a number of interesting possibilities: (i) a formal model for a language that can talk about the meaning of its own expressions (the language as its own metalanguage), (ii) quantification over syntactical terms; iii) an alternative semantics for the mathematical discourse, (iv) proof-theoretic semantics as a special case of algorithmic semantics.
This is joint work with Francisco G. Martins e Francicleber M. Ferreira.
Complexity of bounded-degree fixed-points (Francicleber M. Ferreira)
The characterization of the expressive power of logics over finite structures sheds light on the connections between finite model theory and complexity theory, making it possible to transfer results and insights from one side to the other. In particular, questions about the separation of complexity classes reduce to questions regarding the separation of logics with respect to expressive power. Also, the logical characterization of complexity classes, in the spirit of descriptive complexity, provides a machine-independent representation of such classes and provides decidable languages where all problems in a complexity class can be expressed. In this work we investigate the complexity of problems expressible by fixed-point logics where both the fixed-points computed and the structures over which problems are defined have bounded Gaifman degree, which are related to linear time complexity.
Congruential filter pairs and their relation with Leibniz operator (Darllan C. Pinto)
We consider the special case of filter pairs (G,i) where the functor G = Co_K is given by congruences relative to some quasivariety K , and give criteria when the associated logic is protoalgebraic, equivalential, algebraizable, truth- equational, self-extentional or Lindenbaum algebraizable, by just analyzing the relation between Leibniz operator and the adjoint of i , improving our previous results. Also, we give a way of producing a logic from a quasivariety and a given set of equations, yielding many interesting new logics. We introduce a notion of morphism of filter pairs and show that it encodes translations between their associated logics. Moreover, we show that the category of abstract logics is isomorphic to a full and reflective subcategory of the category of filter pairs.
This is joint work with Peter Arndt, Ramon Jansana and Hugo Luiz Mariano.
Logic, epistemology and information (Samir Gorsky)
The objective of this communication is to extend the concept of semantics for the context of modal logic. This work is situated in the field of research on logic and information which, in turn, is a branch of philosophy of information. The references that will be used for this purpose include works of Bar-Hillel, Carnap, D’Agostino, Floridi, Hintikka and the speaker himself.
Chair: Samuel Gomes da Silva - Grupo de Lógica, Conjuntos e Topologia (UFBA), Membro da Diretoria da SBL
17:30h-17:55h | Abílio A. Rodrigues Filho (UFMG) | TBA |
18:00h-18:25h | Samir Gorsky (UFRN) | Logic, epistemology and information |
18:30h-19:10h | Maximo Dickmann (Paris 7) | TBA |
17h30-17h55 Prof. Dr. Abílio A. Rodrigues Filho
TBA
18h00-18h25 Prof. Dr. Samir Gorsky (UFRN)
LOGIC, EPISTEMOLOGY AND INFORMATION
Abstract: The objective of this communication is to extend the concept of semantics for the context of modal logic. This work is situated in the field of research on logic and information which, in turn, is a branch of philosophy of information. The references that will be used for this purpose include works of Bar-Hillel, Carnap, D’Agostino, Floridi, Hintikka and the speaker himself.
18h30-19h10 Prof. Dr. Maximo Dickmann (Paris 7)
TBA
Chair: Prof. Dr. Samuel Gomes da Silva - Grupo de Lógica, Conjuntos e Topologia (UFBA)
Membro da Diretoria da SBL
Logic, epistemology and information (Samir Gorsky)
The objective of this communication is to extend the concept of semantics for the context of modal logic. This work is situated in the field of research on logic and information which, in turn, is a branch of philosophy of information. The references that will be used for this purpose include works of Bar-Hillel, Carnap, D’Agostino, Floridi, Hintikka and the speaker himself.
Chair: Samuel Gomes da Silva - Grupo de Lógica, Conjuntos e Topologia (UFBA), Membro da Diretoria da SBL
16:30h-17:00h | Coffee break | |
17:00h-17:25h | Darllan C. Pinto (UFBA) | Congruential filter pairs and their relation with Leibniz operator |
16h30-17h00 Café
17h00-17h25 Prof. Dr. Darllan C. Pinto (UFBA)
CONGRUENTIAL FILTER PAIRS AND THEIR RELATION WITH LEIBNIZ OPERATOR
Abstract: We consider the special case of filter pairs (G,i) where the functor G = Co_K is given by congruences relative to some quasivariety K , and give criteria when the associated logic is protoalgebraic, equivalential, algebraizable, truth- equational, self-extentional or Lindenbaum algebraizable, by just analyzing the relation between Leibniz operator and the adjoint of i , improving our previous results. Also, we give a way of producing a logic from a quasivariety and a given set of equations, yielding many interesting new logics. We introduce a notion of morphism of filter pairs and show that it encodes translations between their associated logics. Moreover, we show that the category of abstract logics is isomorphic to a full and reflective subcategory of the category of filter pairs.
Congruential filter pairs and their relation with Leibniz operator (Darllan C. Pinto)
We consider the special case of filter pairs (G,i) where the functor G = Co_K is given by congruences relative to some quasivariety K , and give criteria when the associated logic is protoalgebraic, equivalential, algebraizable, truth- equational, self-extentional or Lindenbaum algebraizable, by just analyzing the relation between Leibniz operator and the adjoint of i , improving our previous results. Also, we give a way of producing a logic from a quasivariety and a given set of equations, yielding many interesting new logics. We introduce a notion of morphism of filter pairs and show that it encodes translations between their associated logics. Moreover, we show that the category of abstract logics is isomorphic to a full and reflective subcategory of the category of filter pairs.
Informações importantes
Sobre o evento
O Workshop realizar-se-á no Auditório do Instituto de Matemática e Estatística da UFBA, na mesma semana em que ocorrem em Salvador outros dois eventos relacionados à Lógica (e organizados pelo Prof. Dr. Abel Lassale Casanave, do Departamento de Filosofia da UFBA):
O Workshop realizar-se-á no Auditório do Instituto de Matemática e Estatística da UFBA, na mesma semana em que ocorrem em Salvador outros dois eventos relacionados à Lógica (e organizados pelo Prof. Abel Lassale Casanave, do Departamento de Filosofia da UFBA):
PROGRAMAÇÃO DO WORKSHOP
14h-14h40 Prof. Dr. Cezar Mortari (UFSC, atual presidente da SBL)
TBA
14h50-15h30 Prof. Dr. Walter Carnielli (CLE/UNICAMP)
THE PRINCIPLE OF ARIADNE AND THE AXIOM OF CHOICE
Abstract: I intend to survey some results on combinatorial aspects of infinite Ramsey-type problems inspired by finite properties, discussing the relevance of an alternative set-theoretical principle, the so-called “Principle of Ariadne”. This principle, a rival of the Axiom of Choice and connected to the polarized partition relations, can be consistently added to the usual axiomatic stock of ZF set theory under certain conditions. The new axiom, which preserves all the finite contents of mathematics but deviates from the standard in the infinite contents, may help us to understand the finite-infinite divide in mathematics, making clear that there is more than one way to generalize from finite principles of order (or choice) to the infinite.
Programação
Horário | Palestrante | Título |
14:00h-14:40h | Cezar Mortari (UFSC, atual presidente da SBL) | TBA |
14:50h-15:30h | Walter Carnielli (CLE/UNICAMP) | The principle of the Ariadne and the Axiom of choice |
15:35h-16:00h | Carlos Brito (UFC) | Talking about Meaning: an algorithmic approach to semantics |
16:05h-16:30h | Francicleber M. Ferreira (UFC) | Complexity of bounded-degree fixed-points |
Resumos das palestras
The principle of the Ariadne and the Axiom of choice (Walter Carnielli)
I intend to survey some results on combinatorial aspects of infinite Ramsey-type problems inspired by finite properties, discussing the relevance of an alternative set-theoretical principle, the so-called “Principle of Ariadne”. This principle, a rival of the Axiom of Choice and connected to the polarized partition relations, can be consistently added to the usual axiomatic stock of ZF set theory under certain conditions. The new axiom, which preserves all the finite contents of mathematics but deviates from the standard in the infinite contents, may help us to understand the finite-infinite divide in mathematics, making clear that there is more than one way to generalize from finite principles of order (or choice) to the infinite.
15h35-16h00 Prof. Dr. Carlos Brito (UFC)
TALKING ABOUT MEANING: AN ALGORITHMIC APPROACH TO SEMANTICS
Abstract: The terms in the natural language are typically used to designate objects in the world. However, an important characteristic of natural languages is precisely the fact that they are capable of speaking not only of the objects in the world, but also of language itself, as well as the speakers of the language. The starting point for the development of our proposed notion of algorithmic semantics is the observation that it doesn’t make sense, in some cases, to understand any term as a name for the corresponding sentence or proposition that would exist in the domain of objects. Such terms do not refer to an object, but are themselves the objects which are being talked about. Next, we observe that linguistic objects do not have the same nature as the objects of the world: their properties are not assessed through perceptual inspection, but are defined by the conventional rules of the language. These two observations give rise to the idea of a semantic value that is produced by the execution of an algorithm which verifies a set of rules. The notion of algorithmic semantics opens the way to a number of interesting possibilities: (i) a formal model for a language that can talk about the meaning of its own expressions (the language as its own metalanguage), (ii) quantification over syntactical terms; iii) an alternative semantics for the mathematical discourse, (iv) proof-theoretic semantics as a special case of algorithmic semantics.
Talking about Meaning: an algorithmic approach to semantics (Carlos Brito)
The terms in the natural language are typically used to designate objects in the world. However, an important characteristic of natural languages is precisely the fact that they are capable of speaking not only of the objects in the world, but also of language itself, as well as the speakers of the language. The starting point for the development of our proposed notion of algorithmic semantics is the observation that it doesn’t make sense, in some cases, to understand any term as a name for the corresponding sentence or proposition that would exist in the domain of objects. Such terms do not refer to an object, but are themselves the objects which are being talked about. Next, we observe that linguistic objects do not have the same nature as the objects of the world: their properties are not assessed through perceptual inspection, but are defined by the conventional rules of the language. These two observations give rise to the idea of a semantic value that is produced by the execution of an algorithm which verifies a set of rules. The notion of algorithmic semantics opens the way to a number of interesting possibilities: (i) a formal model for a language that can talk about the meaning of its own expressions (the language as its own metalanguage), (ii) quantification over syntactical terms; iii) an alternative semantics for the mathematical discourse, (iv) proof-theoretic semantics as a special case of algorithmic semantics.
16h05-16h30 Prof. Dr. Francicleber M. Ferreira (UFC)
COMPLEXITY OF BOUNDED-DEGREE FIXED-POINTS
Abstract: The characterization of the expressive power of logics over finite structures sheds light on the connections between finite model theory and complexity theory, making it possible to transfer results and insights from one side to the other. In particular, questions about the separation of complexity classes reduce to questions regarding the separation of logics with respect to expressive power. Also, the logical characterization of complexity classes, in the spirit of descriptive complexity, provides a machine-independent representation of such classes and provides decidable languages where all problems in a complexity class can be expressed. In this work we investigate the complexity of problems expressible by fixed-point logics where both the fixed-points computed and the structures over which problems are defined have bounded Gaifman degree, which are related to linear time complexity.
Complexity of bounded-degree fixed-points (Francicleber M. Ferreira)
The characterization of the expressive power of logics over finite structures sheds light on the connections between finite model theory and complexity theory, making it possible to transfer results and insights from one side to the other. In particular, questions about the separation of complexity classes reduce to questions regarding the separation of logics with respect to expressive power. Also, the logical characterization of complexity classes, in the spirit of descriptive complexity, provides a machine-independent representation of such classes and provides decidable languages where all problems in a complexity class can be expressed. In this work we investigate the complexity of problems expressible by fixed-point logics where both the fixed-points computed and the structures over which problems are defined have bounded Gaifman degree, which are related to linear time complexity.
Membro da Diretoria da SBL
Membro da Diretoria da SBL
Events supported by SBL
Workshop da Sociedade Brasileira de Lógica
- Local: Auditório do Instituto de Matemática e Estatística, UFBA (Salvador-BA)
- Data: 24 de Outubro de 2017, 14:00h
O Workshop da Sociedade Brasileira de Lógica é uma iniciativa da Sociedade Brasileira de Lógica (SBL), consistindo de palestras e comunicações convidadas, com o objetivo de apresentar um painel da pesquisa em Lógica no Brasil (e em particular no Nordeste), em todas as suas vertentes: Filosofia, Ciência da Computação, Matemática.
Os keynote speakers do Workshop são: Cezar Mortari (UFSC, atual Presidente da SBL), Walter Carnielli (UNICAMP) e Maximo Dickmann (Paris 7).
O Workshop realizar-se-á no Auditório do Instituto de Matemática e Estatística da UFBA, na mesma semana em que ocorrem em Salvador outros dois eventos relacionados à Lógica (e organizados pelo Prof. Dr. Abel Lassale Casanave, do Departamento de Filosofia da UFBA):
- o Colóquio Conesul (do Grupo Conesul de Filosofia das Ciências Formais), de 20 a 23 de Outubro, com programação já disponibilizada em http://gcfcf.com.br/pt/coloquios/
- e também o Fourth Meeting APMP (Association for the Philosophy of Mathematical Practice), de 23 a 26 de Outubro, com programação já disponibilizada em http://www.philmathpractice.org/
O Workshop é isento de inscrição. Todos os interessados em participar do Fourth Meeting APMP como ouvintes são solicitados a confirmar sua participação preenchendo a Registration Form e pagando a taxa de inscrição (R$ 150,00) até 30 de setembro. A inscrição no Meeting também permite participação no Colóquio Conesul.
PROGRAMAÇÃO DO WORKSHOP
14h-14h40 Prof. Dr. Cezar Mortari (UFSC, atual presidente da SBL)
TBA
14h50-15h30 Prof. Dr. Walter Carnielli (CLE/UNICAMP)
THE PRINCIPLE OF ARIADNE AND THE AXIOM OF CHOICE
Abstract: I intend to survey some results on combinatorial aspects of infinite Ramsey-type problems inspired by finite properties, discussing the relevance of an alternative set-theoretical principle, the so-called “Principle of Ariadne”. This principle, a rival of the Axiom of Choice and connected to the polarized partition relations, can be consistently added to the usual axiomatic stock of ZF set theory under certain conditions. The new axiom, which preserves all the finite contents of mathematics but deviates from the standard in the infinite contents, may help us to understand the finite-infinite divide in mathematics, making clear that there is more than one way to generalize from finite principles of order (or choice) to the infinite.
This is joint work with Carlos di Prisco.
15h35-16h00 Prof. Dr. Carlos Brito (UFC)
TALKING ABOUT MEANING: AN ALGORITHMIC APPROACH TO SEMANTICS
Abstract: The terms in the natural language are typically used to designate objects in the world. However, an important characteristic of natural languages is precisely the fact that they are capable of speaking not only of the objects in the world, but also of language itself, as well as the speakers of the language. The starting point for the development of our proposed notion of algorithmic semantics is the observation that it doesn’t make sense, in some cases, to understand any term as a name for the corresponding sentence or proposition that would exist in the domain of objects. Such terms do not refer to an object, but are themselves the objects which are being talked about. Next, we observe that linguistic objects do not have the same nature as the objects of the world: their properties are not assessed through perceptual inspection, but are defined by the conventional rules of the language. These two observations give rise to the idea of a semantic value that is produced by the execution of an algorithm which verifies a set of rules. The notion of algorithmic semantics opens the way to a number of interesting possibilities: (i) a formal model for a language that can talk about the meaning of its own expressions (the language as its own metalanguage), (ii) quantification over syntactical terms; iii) an alternative semantics for the mathematical discourse, (iv) proof-theoretic semantics as a special case of algorithmic semantics.
This is joint work with Francisco G. Martins e Francicleber M. Ferreira.
16h05-16h30 Prof. Dr. Francicleber M. Ferreira (UFC)
COMPLEXITY OF BOUNDED-DEGREE FIXED-POINTS
Abstract: The characterization of the expressive power of logics over finite structures sheds light on the connections between finite model theory and complexity theory, making it possible to transfer results and insights from one side to the other. In particular, questions about the separation of complexity classes reduce to questions regarding the separation of logics with respect to expressive power. Also, the logical characterization of complexity classes, in the spirit of descriptive complexity, provides a machine-independent representation of such classes and provides decidable languages where all problems in a complexity class can be expressed. In this work we investigate the complexity of problems expressible by fixed-point logics where both the fixed-points computed and the structures over which problems are defined have bounded Gaifman degree, which are related to linear time complexity.
16h30-17h00 Café
17h00-17h25 Prof. Dr. Darllan C. Pinto (UFBA)
CONGRUENTIAL FILTER PAIRS AND THEIR RELATION WITH LEIBNIZ OPERATOR
Abstract: We consider the special case of filter pairs (G,i) where the functor G = Co_K is given by congruences relative to some quasivariety K , and give criteria when the associated logic is protoalgebraic, equivalential, algebraizable, truth- equational, self-extentional or Lindenbaum algebraizable, by just analyzing the relation between Leibniz operator and the adjoint of i , improving our previous results. Also, we give a way of producing a logic from a quasivariety and a given set of equations, yielding many interesting new logics. We introduce a notion of morphism of filter pairs and show that it encodes translations between their associated logics. Moreover, we show that the category of abstract logics is isomorphic to a full and reflective subcategory of the category of filter pairs.
This is joint work with Peter Arndt, Ramon Jansana and Hugo Luiz Mariano.
17h30-17h55 Prof. Dr. Abílio A. Rodrigues Filho
TBA
18h00-18h25 Prof. Dr. Samir Gorsky (UFRN)
LOGIC, EPISTEMOLOGY AND INFORMATION
Abstract: The objective of this communication is to extend the concept of semantics for the context of modal logic. This work is situated in the field of research on logic and information which, in turn, is a branch of philosophy of information. The references that will be used for this purpose include works of Bar-Hillel, Carnap, D’Agostino, Floridi, Hintikka and the speaker himself.
18h30-19h10 Prof. Dr. Maximo Dickmann (Paris 7)
TBA
Chair: Prof. Dr. Samuel Gomes da Silva - Grupo de Lógica, Conjuntos e Topologia (UFBA)
Membro da Diretoria da SBL