# Logic Seminar

### Organizers: Laurențiu Leuștean, Denisa Diaconescu, Andrei Sipoș

The logic seminar features talks on
mathematical logic,
philosophical logic and
logical aspects of computer science.
All seminars, except where otherwise indicated,
will be at 10:00 in Hall 202,
Faculty of Mathematics and Computer Science,
University of Bucharest.
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our group

## Talks in 2018-2019

### Thursday, December 6, 2018

Roberto Giuntini (University of Cagliari)
Classical and quantum degrees of truth: a new look at the effects of a Hilbert space

Abstract: We investigate certain Brouwer-Zadeh lattices that serve as abstract counterparts of lattices of effects in Hilbert spaces under the spectral ordering. These algebras, called $PBZ^*$-lattices, can also be seen as generalisations of orthomodular lattices and are remarkable for the collapse of three notions of “sharpness” that are distinct in general Brouwer-Zadeh lattices. We investigate the structure theory of $PBZ^*$-lattices and their reducts; in particular, we prove some embedding results for $PBZ^*$-lattices and provide an initial description of the lattice of $PBZ^*$-varieties.