102 research outputs found
Topics in Programming Languages, a Philosophical Analysis through the case of Prolog
[EN]Programming languages seldom find proper anchorage in philosophy of logic, language and science. is more, philosophy of language seems to be restricted to natural languages and linguistics, and even philosophy of logic is rarely framed into programming languages topics. The logic programming paradigm and Prolog are, thus, the most adequate paradigm and programming language to work on this subject, combining natural language processing and linguistics, logic programming and constriction methodology on both algorithms and procedures, on an overall philosophizing declarative status. Not only this, but the dimension of the Fifth Generation Computer system related to strong Al wherein Prolog took a major role. and its historical frame in the very crucial dialectic between procedural and declarative paradigms, structuralist and empiricist biases, serves, in exemplar form, to treat straight ahead philosophy of logic, language and science in the contemporaneous age as well.
In recounting Prolog's philosophical, mechanical and algorithmic harbingers, the opportunity is open to various routes. We herein shall exemplify some:
- the mechanical-computational background explored by Pascal, Leibniz, Boole, Jacquard, Babbage, Konrad Zuse, until reaching to the ACE (Alan Turing) and EDVAC (von Neumann), offering the backbone in computer architecture, and the work of Turing, Church, Gödel, Kleene, von Neumann, Shannon, and others on computability, in parallel lines, throughly studied in detail, permit us to interpret ahead the evolving realm of programming languages. The proper line from lambda-calculus, to the Algol-family, the declarative and procedural split with the C language and Prolog, and the ensuing branching and programming languages explosion and further delimitation, are thereupon inspected as to relate them with the proper syntax, semantics and philosophical élan of logic programming and Prolog
Natural Communication
In Natural Communication, the author criticizes the current paradigm of specific goal orientation in the complexity sciences. His model of "natural communication" encapsulates modern theoretical concepts from mathematics and physics, in particular category theory and quantum theory. The author is convinced that only by looking to the past is it possible to establish continuity and coherence in the complexity science
Proceedings of the 1968 Summer Institute on Symbolic Mathematical Computation
Investigating symbolic mathematical computation using PL/1 FORMAC batch system and Scope FORMAC interactive syste
The physical cosmology of Alfred North Whitehead
Throughout the history of philosophy, cosmological
theories have always deservedly enjoyed a position of
special prominence. Of all recent cosmologies, or phi - losophies of Nature, perhaps the most comprehensive and
satisfactory is that offered. by Alfred North Whitehead.
Whitehead, always both mathematician and philosopher,
enjoyed a full career as mathematician at Cambridge and
London Universities before answering an invitation from
Harvard University to a chair in philosophy there. His
interests invariably carried him to the forefront of the
advance, and his more technical mathematical works bore
the imprint of a philosopher. His philosophy carried the
marks of its birth in mathematics and the physical sciences.Although his Treatise on Universal Algebra (1898) won
him an enviable reputation, it was his collaboration with
Bertrand Russell in the first decade of the twentieth century on Principia Nathematica which proved his pioneering
genius. In the middle of this decade, Whitehead offered
to the Royal Society of London a memoir entitled "On
Mathematical Concepts of the Material World." This memoir,
which fell into oblivion, employed the symbolic technique
of Principia Nathematica in solving the fundamental problem of importance to cosmological theory. Given a set of
entities and a relation between those entities, Whitehead
attempted to show the whole of Euclidean geometry to be an
expression of the properties of the field of that relation. Certain extraneous relations served to associate
the axioms with the material world of the physicists, of
which Whitehead offered seven alternative concepts.The first three volumes of Princiaá Mathematica had
been published, and Whitehead had begun his work on the
fourth, which was to have been concerned with the application of symbolic reasoning to the foundations of geometry
and the problem of space. But by this time the scientific
world had been captivated by the publication of the special and general theories of relativity by Einstein.
These novelties naturally attracted Whitehead, who wrote
several essays on the presuppositions of relativity.
Whitehead was convinced that the principle and the method
introduced by Einstein constituted a revolution in physical science, but found his explanation faulty.A series of three important "Nature" volumes introduced the philosophy of "Nature" as conceived by Whitehead,
using his own interpretation of the meaning of the new
relativity. A powerful method of analysis, called the
Method of Extensive Abstraction and having as its purpose
the definition of spatial and temporal entities so as to
avoid a circularity of reasoning was born at this period.
The third of the volumes was devoted entirely to the development of his own theory of relativity, to which the
philosophically more satisfactory interpretation of relativity could be readily applied. From his original presuppositions Whitehead offered four alternative relativity
theories, one of which coincided with Einstein's, and two
of which were attempts at a unified field theory. The
fourth, a theory of gravitation, used a physical element,
the "impetus," instead of an infinitesimal metric element,
as Einstein had done. This theory proved to be empirically
less satisfactory than that of Einstein. But Professor
George Temple generalized this fourth theory by using a space -time of positive uniform curvature, and results more
satisfactory empirically than those of Einstein followed.
The philosophical advantages of Whitehead's relativity
were retained. This result seems to invite a more careful
consideration of Temple's generalization of ;Whitehead's
relativity than has been obtained at present.But by this time Whitehead's speculations, which took
as their restricted field the area of nature in which mind
was irrelevant, began to concentrate on the enlarged field
of cosmological theory in its points of contact with metaphysics. The most important discovery he believed he had
made was that in this enlarged area, all the more special
physical and extensive properties of nature were dependent
for their existence upon process.Now in his sixties, Whitehead accepted Harvard's invitation to a chair in philosophy. Within a very few
years he returned to the United Kingdom to deliver the
Gifford Lectures at the University of Edinburgh, in which
the implications of adopting process as the central principle in the universe were systematically presented.One outstanding; feature of these lectures has been
unfortunately ignored; it is a major and original suggestion of this thesis that the categoreal scheme of Process
and Reality is really the axiomatic scheme of "On Mathematical Concepts of the Material World" generalized on the
metaphysical level. An attempt at the application of the
symbolic method to the axioms (categories of explanation
and obligation) is made here. Thus the generalized problem in Process and Reality becomes, "Given a set of onto - logical existents and the operation of creativity, what
axioms regarding the operation of creativity will have as
their result that the more specialized discoveries of the
humanities and the sciences follow from the properties of
those entities forming the field of creativity?"These lectures, although they offered a comprehensive
metaphysical system justifying the operation of physical
field theories, suffered under the misfa' tune that they
were given at just the time when the quantum mechanics
revolution was precipitated in the physical sciences.
From the point of view of quantum mechanics, therefore,
the philosophy of organism does not supply a satisfactory
cosmology within which it can operate. This is especially
unfortunate in view of his possibly superior physical
theory of relativity; possible points of expansion to allow for quantum mechanics are indicated, although they do
violence to the base of the philosophy of organism.As the chief exemplification of the metaphysical
principles, Whitehead postulated a brilliantly conceived
metaphysical God who was important in physical cosmology.
It is suggested that this metaphysical God is, nevertheless, inadequate to satisfy the demands of the religious
conscience.Despite the originality of most of the elements introduced by Whitehead, a full understanding of his meaning
and an appreciation of his novelties is possible only by
referring his writings to their proper settings. Thus,
the philosophy of organism is explained against the background of the process philosophies of Bergson, Alexander,
and Horgan. Because of its many similarities in respect
to the setting of the cosmological problem and the essentials of the solution to the Timaeus, a special chapter is
devoted to the correspondence between the two. Whitehead's
relativity and philosophy of Nature requires an understanding of the development of the theory of relativity, the
world- models of the relativistic cosmologies, and the attempts at a unified field theory. Similarly, the memoir
of 1905 is described in a more general back ground setting
forth a broad picture of the state of geometry, physical
science, and philosophy at the turn of the century.As a final reflection, certain presuppositions at the
base of Whitehead's philosophy of organism are investigated and evaluated. The points believed by the present
writer to be especially vulnerable in the philosophy of
organism are exposed. An experiment in suggesting the
prospectus of an alternative system which might avoid the
difficulties, and incorporate the advantages of, the philosophy of organism, is made with the warning that it is
no more than a suggestion.Throughout the thesis, certain dominant strains of
"Ihitehead's thinking can be detected: the importance in
his mind of the axiomatic -deductive method in the sciences;
the realization that prevalent habits of thinking need to
be altered by new discoveries, but are resisted; the conviction that the sciences must be ontologically centered;
the faith in field theories; and the conviction that cosmology must be the search for the forms in the facts; to
designate the more outstanding convictions
Elastodynamics of Failure in a Continuum
A general treatment of the elastodynamics of failure in a
prestressed elastic continuum is given, with particular emphasis on the geophysical aspects of the problem. The principal purpose of the study is to provide a physical model of the earthquake phenomenon, which yields an explicit description of the radiation field in terms of source parameters.
The Green's tensor solution to the equations of motion in a medium with moving boundaries is developed. Using this representation theorem, and its specialization to the scalar case by means of potentials, it is shown that material failure in a continuum can be treated equivalently
as a boundary value problem or as an initial value problem. The initial value representation is shown to be preferable for geophysical purposes, and the general solution for a growing and propagating rupture zone is given.
The energy balance of the phenomenon is discussed with particular emphasis on the physical source of the radiated energy. It is also argued that the flow of energy is the controlling factor for the propagation and growth of a failure zone. Failure should then be viewed as a generalized phase change of the medium.
The theory is applied to the simple case of a growing and propagating spherical failure zone. The model is investigated in detail both analytically and numerically. The analysis is performed in the frequency domain and the radiation fields are given in the form of multipolar expansions. The necessary theorems for the manipulation of
such expansions for seismological purposes are proved, and their use discussed on the basis of simple examples.
The more realistic ellipsoidal failure zone is investigated. The static problem of an arbitrary ellipsoidal inclusion under homogeneous stress of arbitrary orientation is solved. It is then shown how the
analytical solution can be combined with numerical techniques to yield more realistic models.
The conclusion is that this general approach yields a very flexible model which can be adapted to a wide variety of physical circumstances. In spite of the simplicity of the model, the predicted radiation field is rather complex; it is discussed as a function of source parameters, and scaling laws are derived which ease the interpretation of observed spectra. Preliminary results in the time domain are also shown. It is concluded that the model can be compared favorably both with the observations, and with results obtained from purely numerical models
Social work with airports passengers
Social work at the airport is in to offer to passengers social services. The main
methodological position is that people are under stress, which characterized by a
particular set of characteristics in appearance and behavior. In such circumstances
passenger attracts in his actions some attention. Only person whom he trusts can help him
with the documents or psychologically
The Principles of Mathematics
Published in 1903, this book was the first comprehensive treatise on the logical foundations of mathematics written in English. It sets forth, as far as possible without mathematical and logical symbolism, the grounds in favour of the view that mathematics and logic are identical. It proposes simply that what is commonly called mathematics are merely later deductions from logical premises. It provided the thesis for which _Principia Mathematica_ provided the detailed proof, and introduced the work of Frege to a wider audience. In addition to the new introduction by John Slater, this edition contains Russell's introduction to the 1937 edition in which he defends his position against his formalist and intuitionist critic
Algorithms, abstraction and implementation : a massively multilevel theory of strong equivalence of complex systems
This thesis puts forward a formal theory of levels and
algorithms to provide a foundation for those terms as
they are used in much of cognitive science and computer
science. Abstraction with respect to concreteness is
distinguished from abstraction with respect to detail,
resulting in three levels of concreteness and a large
number of algorithmic levels, which are levels of detail
and the primary focus of the theory.
An algorithm or ideal machine is a set of sequences of
states defining a particular level of detail. Rather
than one fundamental ideal machine to describe the
behaviour of a complex system, there are many possible
ideal machines, extending Turing's approach to reflect
the multiplicity of system descriptions required to
express more than weak input-output equivalence of
systems. Cognitive science is concerned with stronger
equivalence; e.g., do two models go through the same
states at some level of description? The state-based
definition of algorithms serves as a basis for such
strong equivalence and facilitates formal renditions of
abstraction and implementation as relations between
algorithms. It is possible to prove within the new
framework whether or not one given algorithm is a valid
implementation of another, or whether two unequal
algorithms have a common abstraction, for example. Some
implications of the theory are discussed, notably a
characterisation of connectionist versus classical
models
The Significance of Evidence-based Reasoning in Mathematics, Mathematics Education, Philosophy, and the Natural Sciences
In this multi-disciplinary investigation we show how an evidence-based perspective of quantification---in terms of algorithmic verifiability and algorithmic computability---admits evidence-based definitions of well-definedness and effective computability, which yield two unarguably constructive interpretations of the first-order Peano Arithmetic PA---over the structure N of the natural numbers---that are complementary, not contradictory. The first yields the weak, standard, interpretation of PA over N, which is well-defined with respect to assignments of algorithmically verifiable Tarskian truth values to the formulas of PA under the interpretation. The second yields a strong, finitary, interpretation of PA over N, which is well-defined with respect to assignments of algorithmically computable Tarskian truth values to the formulas of PA under the interpretation. We situate our investigation within a broad analysis of quantification vis a vis: * Hilbert's epsilon-calculus * Goedel's omega-consistency * The Law of the Excluded Middle * Hilbert's omega-Rule * An Algorithmic omega-Rule * Gentzen's Rule of Infinite Induction * Rosser's Rule C * Markov's Principle * The Church-Turing Thesis * Aristotle's particularisation * Wittgenstein's perspective of constructive mathematics * An evidence-based perspective of quantification. By showing how these are formally inter-related, we highlight the fragility of both the persisting, theistic, classical/Platonic interpretation of quantification grounded in Hilbert's epsilon-calculus; and the persisting, atheistic, constructive/Intuitionistic interpretation of quantification rooted in Brouwer's belief that the Law of the Excluded Middle is non-finitary. We then consider some consequences for mathematics, mathematics education, philosophy, and the natural sciences, of an agnostic, evidence-based, finitary interpretation of quantification that challenges classical paradigms in all these disciplines
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