We introduce two generalized condensation principles: Local Club Condensation and Stationary Condensation. We show that while Strong Condensation (a generalized condensation principle introduced by Hugh Woodin) is inconsistent with an ω₁-Erdős cardinal, Stationary Condensation and Local Club Condensation (which should be thought of as weakenings of Strong Condensation) are both consistent with ω-superstrong cardinals.
Effect basic algebras (which correspond to lattice ordered effect algebras) are studied. Their ideals are characterized (in the language of basic algebras) and one-to-one correspondence between ideals and congruences is shown. Conditions under which the quotients are OMLs or MV-algebras are found.
If G is a countable group containing a copy of F₂ then the conjugacy equivalence relation on subgroups of G attains the maximal possible complexity.
Si determinano alcune restrizioni sulle possibili cardinalità dei modelli di teorie in logiche soddisfacenti alcune proprietà di compattezza. Si dà una caratterizzazione delle logiche -compatte generate da quantificatori di cardinalità. Si stabilisce che il primo cardinale tale che una logica è -compatta è debolmente inaccessibile e soddisfa la proprietà dell'albero. Dai risultati enunciati appare un raffronto assai particolareggiato fra i due concetti di -compattezza e -compattezza.
Given a real separable Hilbert space H, we denote with S = {E(n) | n belongs to N} a sequence of closed linear subspaces of H.In previous papers, the strong, weak, a--> and b--> convergences are defined and characterized. Now, given a sequence S with strong, weak, a--> or b--> limit, and a linear operator of H, A, the sequence AS is studied.
In this article, conservation rules of the direct sum decomposition of groups are mainly discussed. In the first section, we prepare miscellaneous definitions and theorems for further formalization in Mizar [5]. In the next three sections, we formalized the fact that the property of direct sum decomposition is preserved against the substitutions of the subscript set, flattening of direct sum, and layering of direct sum, respectively. We referred to [14], [13] [6] and [11] in the formalization.
A degree of probabilistic dependence is introduced in the classical logic using the Frank family of -norms known from fuzzy logics. In the quantum logic a degree of quantum dependence is added corresponding to the level of noncompatibility. Further, in the case of the fuzzy logic with -states, (resp. -states) the consideration turned out to be fully analogous to (resp. considerably different from) the classical situation.
Silver’s fundamental dichotomy in the classical theory of Borel reducibility states that any Borel (or even co-analytic) equivalence relation with uncountably many classes has a perfect set of classes. The natural generalisation of this to the generalised Baire space for a regular uncountable κ fails in Gödel’s L, even for κ-Borel equivalence relations. We show here that Silver’s dichotomy for κ-Borel equivalence relations in for uncountable regular κ is however consistent (with GCH), assuming...