DAGNINO , Francesco

We study the extent to which it is possible to approximate the optimal value of a Unique Games instance in Fixed -Point Logic with Counting (FPC). Formally, we prove lower bounds against the accuracy of FPC-interpretations that map Unique Games instances (encoded as relational structures) to rational numbers giving the approximate fraction of...

This short paper describes :DRHOP , a project proposal based on the idea of an "open interface" that aims to aggregate different types of "services" and to build around them a community of users who, without changing their usual online (and offline) habits, collect a wallet of drops, a sort of virtual currency that can be donated for charity...

Doctrines are categorical structures very apt to study logics of different nature within a unified environment: the 2-category Dtn of doctrines. Modal interior operators are characterised as particular adjoints in the 2-category Dtn. We show that they can be constructed from comonads in Dtn as well as from adjunctions in it, and we compare the...

We face the problem of providing a denotational semantics for corecursive methods with default, a programming feature for manipulating cyclic structures without ad-hoc machinery. To this aim, we study new lattices for which the theorem of Kleene is applicable so that the semantics of a corecursive method with default corresponds to the greatest...