arXiv subjects

Paola Cattabriga

Publications and source records attributed to Paola Cattabriga.

8 recordsLinked to original sources

arXiv2025

A note reviewing Turing's 1936

By closely rereading the original Turing's 1936 article, we can gain insight about that it is based on the claim to have defined a number which is not computable, arguing that there can be no machine computing the diagonal on the enumeration of the computable sequences. This article provides a careful analysis of Turing's original argument, demonstrating that it cannot be regarded as a conclusive proof. Furthermore, it shows that there is no evidence supporting the existence of a defined number that is not computable.

cs.CC↗

arXiv2024

Reflections on Russell's antinomy

We present Russell's antinomy using three distinct deductive systems, which are then compared to deepen the logical deductions that lead to the contradiction. Some inferential paths are then presented, alternative to the commonly accepted one, that allow for the formal assertion of the antinomy without deriving the contradiction, thus preserving the coherence of the system. In light of this, the purpose of this article is to propose a review of the consequences of asserting Russell's antinomy and, by extension, the widespread belief that any attempt to resolve a paradox is doomed to failure.

math.LO↗

arXiv2024

On Godel's treatment of the undecidable in 1931

In this article we discuss the proof in the short unpublished paper appeared in the 3rd volume of Godel's Collected Works entitled "On undecidable sentences" (*1931?), which provides an introduction to Godel's 1931 ideas regarding the incompleteness of arithmetic. We analyze the meaning of the negation of the provability predicate, and how it is meant not to lead to vicious circle. We show how in fact in Godel's entire argument there is an omission regarding the cases of non-provability, which, once taken into consideration again, allow a completely different view of Godel's entire argument of incompleteness. Previous results of the author are applied to show that the definition of a contradiction is included in the argument of *1931?. Furthermore, an examination of the application of substitution in the well-known Godel formula as a violation of uniqueness is also briefly presented, questioning its very derivation.

math.HO↗

arXiv2024

Refutability as Recursive as Provability

Godel numbering is an arithmetization of sintax which defines provability by coding a primitive recursive predicate, Pf(x,v). A multiplicity of researches and results all around this well-known recursive predicate are today widespread in many areas of logic and AI. Not equally investigated is the refutability predicate defined by Godel numbering within the same primitive recursive status. Rf(x,v) can be defined as a recursive predicate meaning that x is the Godel number of a refutation in PA of the formula with Godel number v. This article proposes a logical investigation of the interactive links between provability and refutability predicates when defined within the same recursive status. The resulting Lemmas are clarifying and open new perspectives for the incompleteness argument and the codings of its underlying notions.

cs.LO↗

arXiv2009

Observations concerning Gödel's 1931

This article demonstrates the invalidity of Theorem VI of Godel's monograph of 1931, showing that propositions (15) and (16), derived from definition (8.1), in its proof, are false in PA. This is achieved in two steps. First, the predicate complementary to the well-known Godel's predicate Bew(x) is ndefined by adding a new relation Wid(x), and new logical connections are accordingly established, Lemma (6). Second, the negations of (15) and (16) are derived by definition (8.1) and Lemma (6). It amounts to saying that (15) and (16) are false and unacceptable for the system. On the account of that, the two well-known cases 1. 17 Gen r is not k-PROVABLE, 2. Neg(17 Gen r) is not k-PROVABLE, can not be drawn, and Theorem VI is therefore invalid.

math.GM↗

arXiv2007

How to release Frege's system from Russell's antinomy

The conditions for proper definitions in mathematics are given, in terms of the theory of definition, on the basis of the criterions of eliminability and non-creativity. As a definition, Russell's antinomy is a violation of the criterion of eliminability (Behmann, 1931; Bochvar, 1943). Following the path of the criterion of non-creativity, this paper develops a new analysis of Comprehension schema and, as a consequence, proof that Russell's antinomy argumentation, despite the words of Frege himself, does not hold in Grundgesetze der Arithmetik. According to Basic Law (III), the class of classes not belonging to themselves is a class defined by a function which can not take as argument its own course of value. In other words, the class of classes not belonging to themselves is a class whose classes are not identical to the class itself.

math.GM↗

arXiv2006

Beyond Uncountable

In 1891 Cantor presented two proofs with the purpose to establish a general theorem that any set can be replaced by a set of greater power. Cantor's power set theorem can be considered to be an extension of Cantor's 1891 second proof and its argument makes use of a well-known self-referring statement. In this article it is shown that, defining the relative complement of the self-referring statement, Cantor's power set theorem cannot be derived. Moreover, it is given a refutation of the first proof, the so-called Cantor's diagonal argument.

math.GM↗

arXiv2006

Beyond Undecidable

The predicate complementary to the well-known Godel's provability predicate is defined. From its recursiveness new consequences concerning the incompleteness argumentation are drawn and extended to new results of consistency, completeness and decidability with regard to Peano Arithmetic and the first order predicate calculus.

math.GM↗