Zobrazeno 1 - 10
of 93
pro vyhledávání: '"Moraschini, T."'
Autor:
Martins, M., Moraschini, T.
For every $n \in \mathbb{N}$, we construct a variety of Heyting algebras, whose $n$-generated free algebra is finite but whose $(n+1)$-generated free algebra is infinite.
Externí odkaz:
http://arxiv.org/abs/2306.15997
We introduce prime products as a generalization of ultraproducts for positive logic. Prime products are shown to satisfy a version of {\L}o\'s's Theorem restricted to positive formulas, as well as the following variant of Keisler Isomorphism Theorem:
Externí odkaz:
http://arxiv.org/abs/2303.02614
A bi-Heyting algebra validates the G\"odel-Dummett axiom $(p\to q)\vee (q\to p)$ iff the poset of its prime filters is a disjoint union of co-trees (i.e., order duals of trees). Bi-Heyting algebras of this kind are called bi-G\"odel algebras and form
Externí odkaz:
http://arxiv.org/abs/2211.14776
For (finitary) deductive systems, we formulate a signature-independent abstraction of the \emph{weak excluded middle law} (WEML), which strengthens the existing general notion of an inconsistency lemma (IL). Of special interest is the case where a qu
Externí odkaz:
http://arxiv.org/abs/2108.09168
The logics RL, RP, and RG have been obtained by expanding Lukasiewicz logic L, product logic P, and G\"odel--Dummett logic G with rational constants. We study the lattices of extensions and structural completeness of these three expansions, obtaining
Externí odkaz:
http://arxiv.org/abs/2108.03049
It is proved that epimorphisms are surjective in a range of varieties of residuated structures, including all varieties of Heyting or Brouwerian algebras of finite depth, and all varieties consisting of Goedel algebras, relative Stone algebras, Sugih
Externí odkaz:
http://arxiv.org/abs/2107.05912
Autor:
Moraschini, T.
A logic is said to admit an equational completeness theorem when it can be interpreted into the equational consequence relative to some class of algebras. We characterize logics admitting an equational completeness theorem that are either locally tab
Externí odkaz:
http://arxiv.org/abs/2107.05069
We prove that there exist profinite Heyting algebras that are not isomorphic to the profinite completion of any Heyting algebra. This resolves an open problem from 2009. More generally, we characterize those varieties of Heyting algebras in which pro
Externí odkaz:
http://arxiv.org/abs/2103.02530
Autor:
Jansana, R., Moraschini, T.
A Leibniz class is a class of logics closed under the formation of term-equivalent logics, compatible expansions, and non-indexed products of sets of logics. We study the complete lattice of all Leibniz classes, called the Leibniz hierarchy. In parti
Externí odkaz:
http://arxiv.org/abs/2002.07792
Autor:
Jansana, R., Moraschini, T.
A notion of interpretation between arbitrary logics is introduced, and the poset Log of all logics ordered under interpretability is studied. It is shown that in Log infima of arbitrarily large sets exist, but binary suprema in general do not. On the
Externí odkaz:
http://arxiv.org/abs/1911.09394