Presburger arithmetic is the first-order theory of the natural numbers with addition. We characterize sets that can be defined by a Presburger formula as exactly the sets whose characteristic functions can be represented by rational generating functions; a geometric characterization of such sets is also given. In addition, ifp= are a subset of the free variables in a Presburger formula, we can define a counting functiong to be the number of solutions to the formula, for a givenp. We (...) show that every counting function obtained in this way may be represented as, equivalently, either a piecewise quasi-polynomial or a rational generating function. Finally, we translate known computational complexity results into this setting and discuss open directions. (shrink)

Students systematically and deliberately apply rule‐based but erroneous algorithms to solving unfamiliar arithmetic problems. These algorithms result in erroneous solutions termed rational errors. Computationally, students' erroneous algorithms can be represented by perturbations or bugs in otherwise correct arithmetic algorithms (Brown & VanLehn, 1980; Langley & Ohilson, 1984; VanLehn, 1983, 1986, 1990; Young S O'Sheo, 1981). Bugs are useful for describing how rational errors occur but bugs are not sufficient for explaining their origin. A possible explanation for (...) this is that rational errors are the result of incorrect induction from examples. This prediction is termed the “induction hypothesis” (VanLehn, 1986). The purpose of the present study was to: (a) expand on post formulations of the induction hypothesis, and (b) use a new methodology to test the induction hypothesis more carefully than has been done previously. The first step involved teaching participants a new number system called NewAbacus, a written modification of the abacus system. The second step consisted of dividing them into different groups, where each individual received an example of only one port of the NewAbacus addition algorithm. During the third and final step, participants were instructed to solve both familiar and unfamiliar types of addition problems in NewAbacus. The induction hypothesis was supported by using both empirical and computational investigations. (shrink)

Solutions to word problems are moderated by the semantic alignment of real-world relations with mathematical operations. Categorical relations between entities are aligned with addition, whereas certain functional relations between entities are aligned with division. Similarly, discreteness vs. continuity of quantities is aligned with different formats for rational numbers. These alignments have been found both in textbooks and in the performance of college students in the USA and in South Korea. The current study examined evidence for alignments in Russia. Textbook (...) analyses revealed semantic alignments for arithmetic word problems, but not for rational numbers. Nonetheless, Russian college students showed semantic alignments both for arithmetic operations and for rational numbers. Since Russian students exhibit semantic alignments for rational numbers in the absence of exposure to examples in school, such alignments likely reflect intuitive understanding of mathematical representations of real-world situations. (shrink)

A real number x is computable iff it is the limit of an effectively converging computable sequence of rational numbers, and x is left computable iff it is the supremum of a computable sequence of rational numbers. By applying the operations “sup” and “inf” alternately n times to computable sequences of rational numbers we introduce a non-collapsing hierarchy {Σn, Πn, Δn : n ∈ ℕ} of real numbers. We characterize the classes Σ2, Π2 and Δ2 in various (...) ways and give several interesting examples. (shrink)

This paper provides examples in arithmetic of the account of rational intuition and evidence developed in my book After Gödel: Platonism and Rationalism in Mathematics and Logic . The paper supplements the book but can be read independently of it. It starts with some simple examples of problem-solving in arithmetic practice and proceeds to general phenomenological conditions that make such problem-solving possible. In proceeding from elementary ‘authentic’ parts of arithmetic to axiomatic formal arithmetic, the paper (...) exhibits some elements of the genetic analysis of arithmetic knowledge that is called for in Husserl’s philosophy. This issues in an elaboration on a number of Gödel’s remarks about the meaning of his incompleteness theorems for the notion of evidence in mathematics. (shrink)

In this 1835 work, Sarah Porter, née Ricardo shows her enthusiasm for arithmetic, and her concern for teaching it in a way that will develop the pupil's mind: 'There is no branch of early education so admirably adapted to call forth and strengthen the reasoning powers.' She uses the device of a conversation between pupil and teacher, popularised by Jane Marcet, to guide young Edmund from the written symbols for numbers through addition, subtraction, multiplication and division, fractions and decimals, (...) proportion, and square and cube roots. Answers to the questions are provided at the end of the book. A member of the Central Society of Education, which promoted imaginative theories of education instead of rote learning, Mrs Porter reworked her book in 1852 as Rational Arithmetic, a more conventional and less entertaining textbook for use in schools. (shrink)

The paper establishes the general structure of the inconsistent models of arithmetic of [7]. It is shown that such models are constituted by a sequence of nuclei. The nuclei fall into three segments: the first contains improper nuclei: the second contains proper nuclei with linear chromosomes: the third contains proper nuclei with cyclical chromosomes. The nuclei have periods which are inherited up the ordering. It is also shown that the improper nuclei can have the order type of any ordinal, (...) of the rationals, or of any other order type that can be embedded in the rationals in a certain way. (shrink)

This paper continues the investigation of inconsistent arithmetical structures. In $\S2$ the basic notion of a model with identity is defined, and results needed from elsewhere are cited. In $\S3$ several nonisomorphic inconsistent models with identity which extend the (=, $\S4$ inconsistent nonstandard models of the classical theory of finite rings and fields modulo m, i.e. Z m , are briefly considered. In $\S5$ two models modulo an infinite nonstandard number are considered. In the first, it is shown how to (...) model inconsistently the arithmetic of the rationals with all names included, a strengthening of earlier results. In the second, all inconsistency is confined to the nonstandard integers, and the effects on Fermat's Last Theorem are considered. It is concluded that the prospects for a good inconsistent theory of fields may be limited. (shrink)

This paper ties together three threads of discussion about the following question: in accepting a system of axioms S, what else are we thereby warranted in accepting, on the basis of accepting S? First, certain foundational positions in the philosophy of mathematics are said to be epistemically stable, in that there exists a coherent rationale for accepting a corresponding system of axioms of arithmetic, which does not entail or otherwise rationally oblige the foundationalist to accept statements beyond the logical (...) consequences of those axioms. Second, epistemic stability is said to be incompatible with the implicit commitment thesis, according to which accepting a system of axioms implicitly commits the foundationalist to accept additional statements not immediately available in that theory. Third, epistemic stability stands in tension with the idea that in accepting a system of axioms S, one thereby also accepts soundness principles for S. We offer a framework for analysis of sets of implicit commitment which reconciles epistemic stability with the latter two notions, and argue that all three ideas are in fact compatible. (shrink)

This paper explores the model theory of relevant arithmetic, emphasizing the structure of nonstandard natural numbers in the relevant arithmetic R#. In particular, the authors prove the “Alien Intruder Theorem” guaranteeing the existence of a model of R# including the rational numbers in which each rational acts as a nonstandard natural number. The authors conclude by considering some consequences of and open questions about the construction used in the theorem.

In this paper we study the automorphism groups of models of Peano Arithmetic. Kossak, Kotlarski, and Schmerl [9] shows that the stabilizer of an unbounded element a of a countable recursively saturated model of Peano Arithmetic M is a maximal subgroup of Aut if and only if the type of a is selective. We extend this result by showing that if M is a countable arithmetically saturated model of Peano Arithmetic, Ω ⊂ M is a very good (...) interstice, and a ∈ Ω, then the stabilizer of a is a maximal subgroup of Aut if and only if the type of a is selective and rational. (shrink)

In this paper, we are concerned with the arithmetical definability of certain notions of integers and rationals in terms of other notions. The results derived will be applied to obtain a negative solution of corresponding decision problems.In Section 1, we show that addition of positive integers can be defined arithmetically in terms of multiplication and the unary operation of successorS(whereSa=a+ 1). Also, it is shown that both addition and multiplication can be defined arithmetically in terms of successor and the relation (...) of divisibility | (wherex|ymeansxdividesy). (shrink)

Ockham’s ontology of arithmetic, specifically his position on the ontological status of natural numbers, has not yet attracted the attention of scholars. Yet it occupies a central role in his nominalism; specifically, Ockham’s position on numbers constitutes a third part of his ontological reductionism, alongside his doctrines of universals and the categories, which have long been recognized to constitute the first two parts. That is, the first part of this program claims that the very idea of a universal thing (...) is self-contradictory, while the second part asserts that it is more rational to accept only two distinct types of singular things, namely substance and quality. These two elements are incomplete, however, for they do not fully encompass Ockham’s position on what realists take to be abstract objects. For this, one needs the third part of Ockham’s program of ontological reductionism, dealing with numbers, among the most paradigmatic abstract objects for realists. (shrink)

This article considers the meaning of the ancient Chinese magic square Luoshu. It is known that this square is the most ancient of this type of squares. The importance of the magic square in the philosophical tradition and in the whole culture of China is large. The ancient understanding of number differs from the modern one by its dual character, combining the features of philosophical symbolism and mathematical constructions. Unfortunately, modern interpretations of the Luoshu as well as other numerical constructions (...) preserved by the Chinese tradition are too often limited to a superficial statement of their symbolic, “numerological” nature, ignoring the effects of the mathematical structure represented by them. At the same time, some scholars strongly emphasize the intuitive aspects of numerology, which do not presuppose accuracy. On the contrary, Leibniz saw in the Chinese binary system of thinking the beginning of an exact universal language. The author, appealing to the concept of A.A. Krushinskiy, analyzes the arithmetic laws of the structure of the square. The article shows that the magic square Luoshu is not a numbers game. Without any doubt, its main meaning lies in the application of arithmetic. Chinese magic square is an illustrative implementation of one of the main features of Chinese language and traditional thinking – its rational and mathematical basis. The Luoshu square is a vivid example of visual constructivism in the Chinese style of thinking. By means of the magic square’s scheme, the procedure of generalization that is a basis of concepts formation is carried out. This procedure uses a mathematical magic square algorithm based on the numerical codes of the five elements. The quinary spontaneous symbolism is rooted in the Chinese traditional culture of thinking and life order. (shrink)

This book explicates Leibnizian analysis as a search for conditions of intelligibility, and reconsiders his use of principles and methods as well as his account of truth in this way. Via careful reading of well-known, lesser known, and previously unedited texts, it gives a more accurate picture of his philosophical intentions, as well as the relevance of his project to contemporary debate. Two case studies are included, one concerning logic and the other arithmetic; they illustrate a theory of intelligibility (...) that takes as its central notion "possibility for thought", a notion which allows Leibniz to escape certain traps of psychologism, the pseudo-ontology of empiricism, and the empty forms of logicism, and suggests new approaches for contemporary philosophy. "In this remarkable study, Grosholz and Yakira offer a fresh interpretive and conceptual angle on Leibniz's metaphysics. [...] this study deserves high marks for its subtlety, novelty, and creative insight into Leibniz's modes of inquiry as well as for its philosophical acumen." Annals of Science. (shrink)

Meyer and Mortensen’s Alien Intruder Theorem includes the extraor- dinary observation that the rationals can be extended to a model of the relevant arithmetic R♯, thereby serving as integers themselves. Al- though the mysteriousness of this observation is acknowledged, little is done to explain why such rationals-as-integers exist or how they operate. In this paper, we show that Meyer and Mortensen’s models can be identified with a class of ultraproducts of finite models of R♯, providing insights into some of (...) the more mysterious phenomena of the rational models. (shrink)

It is a popular view thatpractical deliberation excludes foreknowledge of one's choice. Wolfgang Spohn and Isaac Levi have argued that not even a purely probabilistic self-predictionis available to thedeliberator, if one takes subjective probabilities to be conceptually linked to betting rates. It makes no sense to have a betting rate for an option, for one's willingness to bet on the option depends on the net gain from the bet, in combination with the option's antecedent utility, rather than on the offered (...) odds. And even apart from this consideration, assigning probabilities to the options among which one is choosing is futile since such probabilities could be of no possible use in choice. The paper subjects these arguments to critical examination and suggests that, appearances notwithstanding, practical deliberation need not crowd outself-prediction. (shrink)

When, how, and why students use conceptual knowledge during math problem solving is not well understood. We propose that when solving routine problems, students are more likely to recruit conceptual knowledge if their procedural knowledge is weak than if it is strong, and that in this context, metacognitive processes, specifically feelings of doubt, mediate interactions between procedural and conceptual knowledge. To test these hypotheses, in two studies (Ns = 64 and 138), university students solved fraction and decimal arithmetic problems (...) while thinking aloud; verbal protocols and written work were coded for overt uses of conceptual knowledge and displays of doubt. Consistent with the hypotheses, use of conceptual knowledge during calculation was not significantly positively associated with accuracy, but was positively associated with displays of doubt, which were negatively associated with accuracy. In Study 1, participants also explained solutions to rational arithmetic problems; using conceptual knowledge in this context was positively correlated with calculation accuracy, but only among participants who did not use conceptual knowledge during calculation, suggesting that the correlation did not reflect “online” effects of using conceptual knowledge. In Study 2, participants also completed a nonroutine problem‐solving task; displays of doubt on this task were positively associated with accuracy, suggesting that metacognitive processes play different roles when solving routine and nonroutine problems. We discuss implications of the results regarding interactions between procedural knowledge, conceptual knowledge, and metacognitive processes in math problem solving. (shrink)

Cantor’s theory of cardinal numbers offers a way to generalize arithmetic from finite sets to infinite sets using the notion of one-to-one association between two sets. As is well known, all countable infinite sets have the same ‘size’ in this account, namely that of the cardinality of the natural numbers. However, throughout the history of reflections on infinity another powerful intuition has played a major role: if a collectionAis properly included in a collectionBthen the ‘size’ ofAshould be less than (...) the ‘size’ ofB(part–whole principle). This second intuition was not developed mathematically in a satisfactory way until quite recently. In this article I begin by reviewing the contributions of some thinkers who argued in favor of the assignment of different sizes to infinite collections of natural numbers (Thabit ibn Qurra, Grosseteste, Maignan, Bolzano). Then, I review some recent mathematical developments that generalize the part–whole principle to infinite sets in a coherent fashion (Katz, Benci, Di Nasso, Forti). Finally, I show how these new developments are important for a proper evaluation of a number of positions in philosophy of mathematics which argue either for the inevitability of the Cantorian notion of infinite number (Gödel) or for the rational nature of the Cantorian generalization as opposed to that, based on the part–whole principle, envisaged by Bolzano (Kitcher). (shrink)

In the second chapter of his book Kant and the Exact Sciences Michael Friedman deals with two different interpretations of the relation or the difference between algebra and arithmetic in Kant's thought. According to the first interpretation algebra can be described as general arithmetic because it generalizes over all numbers by the use of variables, whereas arithmetic only deals with particular numbers. The alternative suggestion is that algebra is more general than arithmetic because it considers a (...) more general class of magnitudes. This means that arithmetic is concerned only with rational magnitudes, whereas algebra is also concerned with irrational magnitudes. In this article, I will discuss which of the two aforementioned approaches is to be considered the most plausible interpretation of Kant's theory of algebra and arithmetic. According to Friedman, the first interpretation cannot be reconciled with certain statements made by Kant on various occasions. The second interpretation is developed by Friedman himself. It is meant to be an attempt to avoid such inconsistencies. By a detailed analysis of the texts Friedman himself cites I shall examine the soundness of his arguments against the first interpretation and the compatibility of his own interpretation of the difference between algebra and arithmetic with the relevant passages in Kant's texts. It will turn out that the reasons that make Friedman reject the first interpretation are invalid as they are based on misunderstandings and that his own interpretation does not expound Kant's notions on that subject correctly, whereas the first interpretation is compatible with these passages. Thus, I conclude that the interpretation rejected by Friedman, unlike his own approach, is actually the more adequate interpretation of Kant. (shrink)

The aim of this study is to try to make use of real numbers for representing an infinite analysis of individual notions in an infinity of possible worlds.As an introduction to the subject, the author shows, firstly, the possibility of representing Boole's lattice of universal notions by an associate Boole's lattice of rational numbers.But, in opposition to the universal notions, definable by a finite number of predicates, an individual notion, cannot admits this sort of definition, because each state of (...) an individual subject is characterized by the values taken by an infinite number of predicates, each of whom may appear or disappear in the next state.The notion of “degree of identification of an individual notion” is then introduced and arithmetized by a rational number.As an individual notion can be defined by a convergent succession of degrees of identification, the real characteristic number of such an individual notion can be defined by the corresponding convergent succession of rational numbers, satisfying Cauchy's conditions for the convergence of successions. (shrink)

Inhaltsverzeichnis/Table of Contents:IntroductionAntónio ZILHÃO: Folk-Psychology, Rationality and Human ActionJoão BRANQUINHO: The Problem of Cognitive DynamicsJ.P. MONTEIRO: Hume, Induction and Single ExperimentsMarco RUFFINO: The Primacy of Concepts and the Priority of Judgments in Frege's LogicJoão Vergílio Gallerani CUTER: Die unanwendbare Arithmetik des TractatusSílvio PINTO: Wittgenstein's Anti-PlatonismFernando FERREIRA: A Substitutional Framework for Arithmetical ValidityJ.R. CROCA & R.N. MOREIRA: Indeterminism Versus CausalismLuíz MONIZ PEREIRA: The Logical Impingement of Artifical Intelligence.

Number concepts must support arithmetic inference. Using this principle, it can be argued that the integer concept of exactly ONE is a necessary part of the psychological foundations of number, as is the notion of the exact equality - that is, perfect substitutability. The inability to support reasoning involving exact equality is a shortcoming in current theories about the development of numerical reasoning. A simple innate basis for the natural number concepts can be proposed that embodies the arithmetic (...) principle, supports exact equality and also enables computational compatibility with real- or rational-valued mental magnitudes. (shrink)

First the expansion of the Łukasiewicz logic by the unary connectives of dividing by any natural number is studied; it is shown that in the predicate case the expansion is conservative w.r.t. witnessed standard 1-tautologies. This result is used to prove that the set of witnessed standard 1-tautologies of the predicate product logic is Π2-hard.

ArgumentTalk of “reason” and “rationality” has been perennial in the philosophy and sciences of the European, Latin tradition since antiquity. But the use of these terms in the early-modern period has left especial marks on the specialties and disciplines that emerged as components of “science” in the modern world. By examining discussions by seventeenth-century philosophers, including natural philosophers such as Descartes, Pascal, and Hobbes, the practical meanings of, specifically, inferential reasoning can be seen as reducing, for most, to intellectual processes (...) deriving from foundations that required intuitional insight that was owing to God. Mechanical reasoning, or artificial intelligence, was a contradiction in terms for such as Pascal, whose views of his own arithmetical machine illustrate the issue well. Hobbes’ analysis of reason, however, replaced the ineffable authority of God with the authority of the civil power, to reveal the social reality of “reason” as nothing other than authorized judgment. (shrink)

In his Foundations of Arithmetic, Frege aims to extend our a priori arithmetical knowledge by answering the question what a natural number is. He rejects conceptual analysis as a method to acquire a priori knowledge . Later he unsuccessfully tried to solve the problems that beset conceptual analysis . If these problems remain unsolved, which rational method can he use to extend our a priori knowledge about numbers? I will argue that his fundamental arithmetical insight that numbers belong (...) to concepts is based on the recognition that different sentences express the same thought. In Frege's philosophy of arithmetic, propositional analysis does the main work. How it can do this work will be discussed in sections 3, 4 and 5. Sections 6 and 7 explore this approach further. (shrink)