Seminars

Links' Seminars and Public Events Add to google calendar
2022
Fri 1st Jul
11:00 am
12:00 pm
Add event to google
Séminaire Arnaud Durand

Fri 10th Jun
10:00 am
11:00 am
Add event to google
Séminaire Corentin Barloy

Title:The Regular Languages of First-Order Logic with One Alternation
Abstract: The regular languages with a neutral letter expressible in first-order logic with one alternation are characterized. Specifically, it is shown that if an arbitrary Σ2 formula defines a regular language with a neutral letter, then there is an equivalent Σ2 formula that only uses the order predicate. This shows that the so-called Central Conjecture of Straubing holds for Σ2 over languages with a neutral letter, the first progress on the Conjecture in more than 20 years. To show the characterization, lower bounds against polynomial-size depth-3 Boolean circuits with constant top fan-in are developed. The heart of the combinatorial argument resides in studying how positions within a language are determined from one another, a technique of independent interest.

Permanent link to this article: https://team.inria.fr/links/seminars/