131 research outputs found
Set theoretical Representations of Integers, I
We reconsider some classical natural semantics of integers (namely iterators
of functions, cardinals of sets, index of equivalence relations), in the
perspective of Kolmogorov complexity. To each such semantics one can attach a
simple representation of integers that we suitably effectivize in order to
develop an associated Kolmogorov theory. Such effectivizations are particular
instances of a general notion of "self-enumerated system" that we introduce in
this paper. Our main result asserts that, with such effectivizations,
Kolmogorov theory allows to quantitatively distinguish the underlying
semantics. We characterize the families obtained by such effectivizations and
prove that the associated Kolmogorov complexities constitute a hierarchy which
coincides with that of Kolmogorov complexities defined via jump oracles and/or
infinite computations. This contrasts with the well-known fact that usual
Kolmogorov complexity does not depend (up to a constant) on the chosen
arithmetic representation of integers, let it be in any base unary, binary et
so on. Also, in a conceptual point of view, our result can be seen as a mean to
measure the degree of abstraction of these diverse semantics.Comment: 56 page
Infinity
This essay surveys the different types of infinity that occur in pure and applied mathematics, with emphasis on: 1. the contrast between potential infinity and actual infinity; 2. Cantor's distinction between transfinite sets and absolute infinity; 3. the constructivist view of infinite quantifiers and the meaning of constructive proof; 4. the concept of feasibility and the philosophical problems surrounding feasible arithmetic; 5. Zeno's paradoxes and modern paradoxes of physical infinity involving supertasks
ON THE FOUNDATIONS OF COMPUTABILITY THEORY
The principal motivation for this work is the observation that there are significant deficiencies in the foundations of conventional computability theory. This thesis examines the problems with conventional computability theory, including its failure to address discrepancies between theory and practice in computer science, semantic confusion in terminology, and limitations in the scope of conventional computing models. In light of these difficulties, fundamental notions are re-examined and revised definitions of key concepts such as “computer,” “computable,” and “computing power” are provided. A detailed analysis is conducted to determine desirable semantics and scope of applicability of foundational notions. The credibility of the revised definitions is ascertained by demonstrating by their ability to address identified problems with conventional definitions. Their practical utility is established through application to examples. Other related issues, including hidden complexity in computations, subtleties related to encodings, and the cardinalities of sets involved in computing, are examined. A resource-based meta-model for characterizing computing model properties is introduced. The proposed definitions are presented as a starting point for an alternate foundation for computability theory. However, formulation of the particular concepts under discussion is not the sole purpose of the thesis. The underlying objective of this research is to open discourse on alternate foundations of computability theory and to inspire re-examination of fundamental notions
Retracing some paths in categorical semantics: From process-propositions-as-types to categorified reals and computers
The logical parallelism of propositional connectives and type constructors
extends beyond the static realm of predicates, to the dynamic realm of
processes. Understanding the logical parallelism of process propositions and
dynamic types was one of the central problems of the semantics of computation,
albeit not always clear or explicit. It sprung into clarity through the early
work of Samson Abramsky, where the central ideas of denotational semantics and
process calculus were brought together and analyzed by categorical tools, e.g.
in the structure of interaction categories. While some logical structures borne
of dynamics of computation immediately started to emerge, others had to wait,
be it because the underlying logical principles (mainly those arising from
coinduction) were not yet sufficiently well-understood, or simply because the
research community was more interested in other semantical tasks. Looking back,
it seems that the process logic uncovered by those early semantical efforts
might still be starting to emerge and that the vast field of results that have
been obtained in the meantime might be a valley on a tip of an iceberg.
In the present paper, I try to provide a logical overview of the gamut of
interaction categories and to distinguish those that model computation from
those that capture processes in general. The main coinductive constructions
turn out to be of this latter kind, as illustrated towards the end of the paper
by a compact category of all real numbers as processes, computable and
uncomputable, with polarized bisimulations as morphisms. The addition of the
reals arises as the biproduct, real vector spaces are the enriched
bicompletions, and linear algebra arises from the enriched kan extensions. At
the final step, I sketch a structure that characterizes the computable fragment
of categorical semantics.Comment: 63 pages, 40 figures; cut two words from the title, tried to improve
(without lengthening) Sec.8; rewrote a proof in the Appendi
Three Dogmas of First-Order Logic and some Evidence-based Consequences for Constructive Mathematics of differentiating between Hilbertian Theism, Brouwerian Atheism and Finitary Agnosticism
We show how removing faith-based beliefs in current philosophies of classical and constructive mathematics admits formal, evidence-based, definitions of constructive mathematics; of a constructively well-defined logic of a formal mathematical language; and of a constructively well-defined model of such a language.
We argue that, from an evidence-based perspective, classical approaches which follow Hilbert's formal definitions of quantification can be labelled `theistic'; whilst constructive approaches based on Brouwer's philosophy of Intuitionism can be labelled `atheistic'.
We then adopt what may be labelled a finitary, evidence-based, `agnostic' perspective and argue that Brouwerian atheism is merely a restricted perspective within the finitary agnostic perspective, whilst Hilbertian theism contradicts the finitary agnostic perspective.
We then consider the argument that Tarski's classic definitions permit an intelligence---whether human or mechanistic---to admit finitary, evidence-based, definitions of the satisfaction and truth of the atomic formulas of the first-order Peano Arithmetic PA over the domain N of the natural numbers in two, hitherto unsuspected and essentially different, ways.
We show that the two definitions correspond to two distinctly different---not necessarily evidence-based but complementary---assignments of satisfaction and truth to the compound formulas of PA over N.
We further show that the PA axioms are true over N, and that the PA rules of inference preserve truth over N, under both the complementary interpretations; and conclude some unsuspected constructive consequences of such complementarity for the foundations of mathematics, logic, philosophy, and the physical sciences
A primordial, mathematical, logical and computable, demonstration (proof) of the family of conjectures known as Goldbach´s
licencia de Creative Commons Reconocimiento-NoComercial-SinObraDerivada 4.0 Internacional.In
this
document,
by
means
of
a
novel
system
model
and
first
order
topological,
algebraic
and
geometrical
free-‐context
formal
language
(NT-‐FS&L),
first,
we
describe
a
new
signature
for
a
set
of
the
natural
numbers
that
is
rooted
in
an
intensional
inductive
de-‐embedding
process
of
both,
the
tensorial
identities
of
the
known
as
“natural
numbers”,
and
the
abstract
framework
of
theirs
locus-‐positional
based
symbolic
representations.
Additionally,
we
describe
that
NT-‐FS&L
is
able
to:
i.-‐
Embed
the
De
Morgan´s
Laws
and
the
FOL-‐Peano´s
Arithmetic
Axiomatic.
ii.-‐
Provide
new
points
of
view
and
perspectives
about
the
succession,
precede
and
addition
operations
and
of
their
abstract,
topological,
algebraic,
analytic
geometrical,
computational
and
cognitive,
formal
representations.
Second,
by
means
of
the
inductive
apparatus
of
NT-‐FS&L,
we
proof
that
the
family
of
conjectures
known
as
Glodbach’s
holds
entailment
and
truth
when
the
reasoning
starts
from
the
consistent
and
finitary
axiomatic
system
herein
describedWe
wish
to
thank
the
Organic
Chemistry
Institute
of
the
Spanish
National
Research
Council
(IQOG/CSIC)
for
its
operative
and
technical
support
to
the
Pedro
Noheda
Research
Group
(PNRG).
We
also
thank
the
Institute
for
Physical
and
Information
Technologies
(ITETI/CSIC)
of
the
Spanish
National
Research
Council
for
their
hospitality.
We
also
thank
for
their
long
years
of
dedicated
and
kind
support
Dr.
Juan
Martínez
Armesto
(VATC/CSIC),
Belén
Cabrero
Suárez
(IQOG/CSIC,
Administration),
Mar
Caso
Neira
(IQOG/CENQUIOR/CSIC,
Library)
and
David
Herrero
Ruíz
(PNRG/IQOG/CSIC).
We
wish
to
thank
to
Bernabé-‐Pajares´s
brothers
(Dr.
Manuel
Bernabé-‐Pajares,
IQOG/CSIC
Structural
Chemistry
&
Biochemistry;
Magnetic
Nuclear
Resonance
and
Dr.
Alberto
Bernabé
Pajares
(Greek
Philology
and
Indo-‐European
Linguistics/UCM),
for
their
kind
attention
during
numerous
and
kind
discussions
about
space,
time,
imaging
and
representation
of
knowledge,
language,
transcription
mistakes,
myths
and
humans
always
holding
us
familiar
illusion
and
passion
for
knowledge
and
intellectual
progress.
We
wish
to
thank
Dr.
Carlos
Cativiela
Marín
(ISQCH/UNIZAR)
for
his
encouragement
and
for
kind
listening
and
attention.
We
wish
to
thank
Miguel
Lorca
Melton
for
his
encouragement
and
professional
point
of
view
as
Patent
Attorney.
Last
but
not
least,
our
gratitude
to
Nati,
María
and
Jaime
for
the
time
borrowed
from
a
loving
husband
and
father.
Finally,
we
apologize
to
many
who
have
not
been
mentioned
today,
but
to
whom
we
are
grateful.
Finally,
let
us
point
out
that
we
specially
apologize
to
many
who
have
been
mentioned
herein
for
any
possible
misunderstanding
regarding
the
sense
and
intension
of
their
philosophic,
scientific
and/or
technical
hard
work
and
milestone
ideas;
we
hope
that
at
least
Goldbach,
Euler
and
Feymann
do
not
belong
to
this
last
human´s
collectivity.Peer reviewe
Epistemic Modality, Mind, and Mathematics
This book concerns the foundations of epistemic modality. I examine the nature of epistemic modality, when the modal operator is interpreted as concerning both apriority and conceivability, as well as states of knowledge and belief. The book demonstrates how epistemic modality relates to the computational theory of mind; metaphysical modality; the types of mathematical modality; to the epistemic status of large cardinal axioms, undecidable propositions, and abstraction principles in the philosophy of mathematics; to the modal profile of rational intuition; and to the types of intention, when the latter is interpreted as a modal mental state. Chapter \textbf{2} argues for a novel type of expressivism based on the duality between the categories of coalgebras and algebras, and argues that the duality permits of the reconciliation between modal cognitivism and modal expressivism. Chapter \textbf{3} provides an abstraction principle for epistemic intensions. Chapter \textbf{4} advances a topic-sensitive two-dimensional truthmaker semantics, and provides three novel interpretations of the framework along with the epistemic and metasemantic. Chapter \textbf{5} applies the fixed points of the modal -calculus in order to account for the iteration of epistemic states, by contrast to availing of modal axiom 4 (i.e. the KK principle). Chapter \textbf{6} advances a solution to the Julius Caesar problem based on Fine's "criterial" identity conditions which incorporate conditions on essentiality and grounding. Chapter \textbf{7} provides a ground-theoretic regimentation of the proposals in the metaphysics of consciousness and examines its bearing on the two-dimensional conceivability argument against physicalism. The topic-sensitive epistemic two-dimensional truthmaker semantics developed in chapter \textbf{4} is availed of in order for epistemic states to be a guide to metaphysical states in the hyperintensional setting. Chapter \textbf{8} examines the modal commitments of abstractionism, in particular necessitism, and epistemic modality and the epistemology of abstraction. Chapter \textbf{9} examines the modal profile of -logic in set theory. Chapter \textbf{10} examines the interaction between epistemic two-dimensional truthmaker semantics, epistemic set theory, and absolute decidability. Chapter \textbf{11} avails of modal coalgebraic automata to interpret the defining properties of indefinite extensibility, and avails of epistemic two-dimensional semantics in order to account for the interaction of the interpretational and objective modalities thereof. The hyperintensional, topic-sensitive epistemic two-dimensional truthmaker semantics developed in chapter \textbf{2} is applied in chapters \textbf{7}, \textbf{8}, \textbf{10}, and \textbf{11}. Chapter \textbf{12} provides a modal logic for rational intuition and provides four models of hyperintensional semantics. Chapter \textbf{13} examines modal responses to the alethic paradoxes. Chapter \textbf{14} examines, finally, the modal semantics for the different types of intention and the relation of the latter to evidential decision theory
The Significance of Evidence-based Reasoning for 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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