Valda Seminar : Val Tannen

Val Tannen, University of Pennsylvania 21 February 2020, 10:00-11:00 ENS, S16 Provenance Analysis for First-order Model Checking Is a given finite structure a model of a given first-order sentence? The provenance analysis of this question determines how its answer depends on the atomic facts that determine the structure. Provenance questions…

Continue reading

Valda Seminar: Nofar Carmeli

Nofar Carmeli, Technion, Israel Institute of Technology 28 February 2020, 10:30-11:30 ENS, S16 The Complexity of Answering Unions of Conjunctive Queries We discuss the complexity of enumerating (listing) the answers to a query over a relational database. In particular, we consider three variants: arbitrary order, uniformly random order, and random…

Continue reading

Valda Seminar: Evgenia Ternovska

Evgenia (Eugenia) Ternovska Associate Professor | School of Computing Science Simon Fraser University 8888 University Dr., Burnaby, B.C. V5A 1S6 13 February 2020, 10:30-11:30 ENS, S16 Logic of Information Flows: Expressing Reachability and Cardinality Properties A challenge in descriptive complexity is to identify logics with low complexity that simultaneously express…

Continue reading

Valda Seminar: Silviu Maniu

Silviu Maniu, Université Paris-Sud 7 February 2020, 10:30-11:30 ENS, S16 An Experimental Study of the Treewidth of Real-World Data Treewidth is a parameter that measures how tree-like a data instance is, and whether it can reasonably be decomposed into a data structure resembling a tree. Many computation tasks are known…

Continue reading