### Séminaire de l'IRIF

**Jour et lieu** : le vendredi de 10h30 à 12h00, *d'habitude* à l'amphi Turing, Bâtiment Sophie Germain (à confirmer dans chaque annonce)

**Responsable** : Adi Rosén

Le séminaire de l'IRIF se decline sous deux series:
**IRIF distinguished talks series** et **IRIF expository talks series**.

Mardi 11 avril 2017 · 10h30 · Amphi Turing

Leonid Libkin (University of Edinburgh) · **IRIF expository talks series**: Primordial database theory revisited: are relational algebra, calculus, and basic SQL really equivalent?

Our goal is to fill these surprising gaps in basic database theory. We provide a formal semantics of the core of SQL that captures the real language and accounts for many of its idiosyncrasies. To justify it as the correct semantics, we validate it experimentally on a large number of randomly generated queries. With this semantics, we formally prove the equivalence of core SQL and RA, as well as the extension of 3-valued FO with an operator that accounts for SQL's ability to switch back and forth between Boolean and 3-valued logics. Then, somewhat surprisingly, we show that this additional operator does not add expressiveness, and - even more surprisingly - that 3-valued logic does not add expressiveness even in the presence of nulls.

Based on joint work with with Paolo Guagliardo.

Vendredi 03 mars 2017 · 10h30 · Amphi Turing

Joost-Pieter Katoen (RWTH Aachen) · **IRIF Distinguished Talks Series**: Principles of Probabilistic Programming (click here for the slides)

Vendredi 28 octobre 2016 · 10h30 · Salle 3052, Bâtiment Sophie Germain (SEE NOTE IN THE ABSTRACT)

Yuri Gurevich (Microsoft Research) · **IRIF expository talks series **: Logic in Computer Science and Computer Engineering

IMPORTANT NOTE: For administrative reasons, those from outside of IRIF who wish to attend the seminar in “Salle 3052” should email by Wednesday 26/10 their name to Irène Guessarian at ig@liafa.univ-paris-diderot.fr .

Vendredi 16 septembre 2016 · 10h30 · Amphi Turing (Bâtiment Sophie Germain)

Roberto di Cosmo (IRIF) · **IRIF expository talks series**: Preserving Software: challenges and opportunities for the reproductibility of Science (click here for the slides)

Preserving this software is of paramount importance to preserve our knowledge.

It is is a necessary prerequisite to allow the replication of experiments, which is the foundation of the scientific method, as well as to ensure our ability to modify and correct the software components that are constantly being incorporated into critical systems that need to stay in production for decades.

In this talk, we will review the challenges and opportunities we are facing, and discuss the role of Open Source as a key enabler.

The slides of the talk can be found here.

Jeudi 28 janvier 2016 · 10h30 · Amphi Turing

Nachum Dershowitz (Tel Aviv University) · Ada and Computation