5 papers
A characterisation of elementary fibrations
Jacopo Emmenegger, Fabio Pasquali, Giuseppe Rosolini
Grothendieck fibrations provide a unifying algebraic framework that underlies the treatment of various form of logics, such as first order logic, higher order logics and dependent…
Aristotle's square of opposition in the light of Hilbert's epsilon and tau quantifiers
Fabio Pasquali, Christian Retoré
Aristotle considered particular quantified sentences in his study of syllogisms and in his famous square of opposition. Of course, the logical formulas in Aristotle work were not m…
Hilbertian Toposes Epsilon Toposes
Fabio Pasquali
We study Hilbert's epsilon calculus and Hilbert's partial epsilon calculus in toposes.
The axiom of choice, co-comprehension schema and redundancies in triposes
Fabio Pasquali
We study the role of the axiom of choice and co-comprehention in second order encoding of first order predicates logic
A tripos based on compact Hausdorff spaces
Fabio Pasquali
The category of compact Hausdorff spaces is the base of tripos. As such it can be freely completed to an elementary topos.