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The Logic seminar is held on Wednesdays, usually at 12-14. During the spring 2022 we coninue continue alternating between online and on campus talks.

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The seminar is led by prof. Juha Kontinen and Juliette Kennedy.

Schedule of the spring term 2022


Wednesday 19.1.2022 12-14, C124: Seminar is cancelled


Miika Hannula IN PERSON, with a zoom link (TBA) provided for those following remotely Wednesday 26.1.2022 12-14, Online

Miika Hannula

Title: "A Dichotomy in Consistent Query Answering for Primary Keys and Unary Foreign Keys", PART 1

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So far, theoretical research in this field has not addressed the combination of primary key and foreign key constraints, despite the importance of referential integrity in database systems. We study CQA with respect to both primary keys and foreign keys, considering the case where foreign keys are unary, and queries are conjunctive queries without self-joins.  In In this setting, it is natural to adopt the notion of symmetric-difference repairs, since foreign keys can be repaired by adding new tuples. We characterize the boundary between those CQA problems that admit a first-order rewriting, and those that do not. This work is closely connected with dependence logic, since primary and foreign keys correspond keys correspond respectively to dependence and inclusion atoms.

This is joint work with Jef Wijsen.


Wednesday 262.12.2022 12-14, C124
Miika Hannula IN PERSON, with a zoom link (TBA) provided for those following remotely  Online

Pietro Galliani

Title: The Unsafety of Constancy 

Abstract: Constancy atoms are among the simplest dependency atoms, and adding them only to First Order Logic yields a language ("Constancy Logic") that is not more expressive than First Order Logic itself. However, adding them to First Order Logic together with other atoms can yield surprising results. In this talk, I will discuss the consequences of adding constancy atoms to logics based on Team Semantics. 


Wednesday 9.2.2022 12-14, Online
Menachem Magidor TBA


Wednesday 16.2.2022 12-14

Miika Hannula

Title: "A Dichotomy in Consistent Query Answering for Primary Keys and Unary Foreign Keys", PART 2

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So far, theoretical research in this field has not addressed the combination of primary key and foreign key constraints, despite the importance of referential integrity in database systems. We study CQA with respect to both primary keys and foreign keys, considering the case where foreign keys are unary, and queries are conjunctive queries without self-joins.  In In this setting, it is natural to adopt the notion of symmetric-difference repairs, since foreign keys can be repaired by adding new tuples. We characterize the boundary between those CQA problems that admit a first-order rewriting, and those that do not. This work is closely connected with dependence logic, since primary and foreign keys correspond keys correspond respectively to dependence and inclusion atoms.

This is joint work with Jef Wijsen.

Wednesday 2.2.2022 12-14, C124

Pietro Galliano

The Unsafety of Constancy 

Constancy atoms are among the simplest dependency atoms, and adding them only to First Order Logic yields a language ("Constancy Logic") that is not more expressive than First Order Logic itself. However, adding them to First Order Logic together with other atoms can yield surprising results. In this talk, I will discuss the consequences of adding constancy atoms to logics based on Team Semantics. 

Wednesday 9.2.2022 12-14, C124
Menachem Magidor TBA

Wednesday 16.2.2022 12-14, C124
TBA


Wednesday 23.2.2022 12-14, C124
Gabe Goldberg TBA  IN PERSON

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