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*                          Einladung
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*                     Informatik-Oberseminar
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Zeit:  Freitag, 23. Juli 2021, 10:00 Uhr
Zoom:  https://rwth.zoom.us/j/97181863376?pwd=VmZIUzlNTXhQRFl0S25uRFBTRW0wdz09

Meeting-ID: 971 8186 3376
Kenncode: 867315

Referent: Richard Wilke, M.Sc.
          LuFG Mathematische Grundlagen der Informatik

Thema: Reasoning about Dependence and Independence: Teams and Multiteams

Abstract:

Team semantics is the mathematical basis of modern logics for reasoning about
dependence and independence. Its core feature is that formulae are evaluated
against a set of assignments, called a team. This approach dates back to Hodges (1997)
who used it to provide a compositional semantics for independence friendly logic.
Building on this idea, Väänänen (2007) suggested that dependencies between variables should
not be treated as annotations of quantifiers, but as atomic properties of teams.
However, being based on sets, team semantics can only be used to reason about the
presence or absence of data. Multiteam semantics instead takes multiplicities of
data into account and is based on multisets of assignments, called multiteams.

In this talk we give an overview of this formalism, explore a wide spectrum of logics
with multiteam semantics and compare them with regard to their expressive power.
We exhibit some striking differences between multiteam and team semantics, and also
show where these formalisms are similar. Moreover, we present a game-theoretic
semantics for our logic and establish connections between logics with multiteam
semantics and variants of existential second-order logic.


Es laden ein: die Dozentinnen und Dozenten der Informatik