65 citations · 149 across the 9 of their papers we have counts for
11 papers
First-Order Interpolation Derived from Propositional Interpolation
Matthias Baaz, Anela Lolic
This paper develops a general methodology to connect propositional and first-order interpolation. In fact, the existence of suitable skolemizations and of Herbrand expansions toget…
Effective Finite-Valued Approximations of General Propositional Logics
Matthias Baaz, Richard Zach
Propositional logics in general, considered as a set of sentences, can be undecidable even if they have "nice" representations, e.g., are given by a calculus. Even decidable propos…
Epsilon Theorems in Intermediate Logics
Matthias Baaz, Richard Zach
Any intermediate propositional logic (i.e., a logic including intuitionistic logic and contained in classical logic) can be extended to a calculus with epsilon- and tau-operators a…
An interpolant in predicate Gödel logic
Matthias Baaz, Mai Gehrke, Sam van Gool
A logic satisfies the interpolation property provided that whenever a formula Δ is a consequence of another formula Γ, then this is witnessed by a formula Θ which only refers to th…
Unsound Inferences Make Proofs Shorter
Juan P. Aguilera, Matthias Baaz
We give examples of calculi that extend Gentzen's sequent calculus LK by unsound quantifier inferences in such a way that (i) derivations lead only to true sequents, and (ii) proof…
Theorem proving for prenex Gödel logic with Delta: checking validity and unsatisfiability
Matthias Baaz, Agata Ciabattoni, Christian G Fermüller
Gödel logic with the projection operator Delta (G_Delta) is an important many-valued as well as intermediate logic. In contrast to classical logic, the validity and the satisfiabil…