53 research outputs found

    Predicativity and parametric polymorphism of Brouwerian implication

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    A common objection to the definition of intuitionistic implication in the Proof Interpretation is that it is impredicative. I discuss the history of that objection, argue that in Brouwer's writings predicativity of implication is ensured through parametric polymorphism of functions on species, and compare this construal with the alternative approaches to predicative implication of Goodman, Dummett, Prawitz, and Martin-L\"of.Comment: Added further references (Pistone, Poincar\'e, Tabatabai, Van Atten

    To the Beat of Different Drumer....Freedom, Anarchy and Conformism in Research

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    In this paper I attempt to make a case for promoting the courage of rebels within the citadels of orthodoxy in academic research environments. Wicksell in Macroeconomics, Brouwer in the Foundations of Mathematics,Turing in Computability Theory, Sraffa in the Theories of Value and Distribution are, in my own fields of research, paradigmatic examples of rebels, adventurers and non-conformists of the highest calibre in scientific research within University environments. In what sense, and how, can such rebels, adventurers and nonconformists be fostered in the current University research environment dominated by the cult of picking winners? This is the motivational question lying behind the historical outlines of the work of Wicksell, Brouwer, Hilbert, Bishop, Veronese, Gödel, Turing and Sraffa that I describe in this paper. The debate between freedom in research and teaching and the naked imposition of correct thinking, on potential dissenters of the mind, is of serious concern in this age of austerity of material facilities. It is a debate that has occupied some the finest minds working at the deepest levels of foundational issues in mathematics, metamathematics and economic theory. By making some of the issues explicit, I hope it is possible to encourage dissenters to remain courageous in the face of current dogmas.Non-conformist research, macroeconomics, foundations of mathematics, intuitionism, constructivism, formalism, Hilbertís Dogma, Hilbertís Program, computability theory

    Computation Environments, An Interactive Semantics for Turing Machines (which P is not equal to NP considering it)

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    To scrutinize notions of computation and time complexity, we introduce and formally define an interactive model for computation that we call it the \emph{computation environment}. A computation environment consists of two main parts: i) a universal processor and ii) a computist who uses the computability power of the universal processor to perform effective procedures. The notion of computation finds it meaning, for the computist, through his \underline{interaction} with the universal processor. We are interested in those computation environments which can be considered as alternative for the real computation environment that the human being is its computist. These computation environments must have two properties: 1- being physically plausible, and 2- being enough powerful. Based on Copeland' criteria for effective procedures, we define what a \emph{physically plausible} computation environment is. We construct two \emph{physically plausible} and \emph{enough powerful} computation environments: 1- the Turing computation environment, denoted by ETE_T, and 2- a persistently evolutionary computation environment, denoted by EeE_e, which persistently evolve in the course of executing the computations. We prove that the equality of complexity classes P\mathrm{P} and NP\mathrm{NP} in the computation environment EeE_e conflicts with the \underline{free will} of the computist. We provide an axiomatic system T\mathcal{T} for Turing computability and prove that ignoring just one of the axiom of T\mathcal{T}, it would not be possible to derive P=NP\mathrm{P=NP} from the rest of axioms. We prove that the computist who lives inside the environment ETE_T, can never be confident that whether he lives in a static environment or a persistently evolutionary one.Comment: 33 pages, interactive computation, P vs N

    Revealing the language of thought

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    Language of thought theories fall primarily into two views. The first view sees the language of thought as an innate language known as mentalese, which is hypothesized to operate at a level below conscious awareness while at the same time operating at a higher level than the neural events in the brain. The second view supposes that the language of thought is not innate. Rather, the language of thought is natural language. So, as an English speaker, my language of thought would be English. My goal is to defend the second view. My methodology will see the project broken down into three major areas. First I will show that human thinking requires a language of thought, after which I will highlight some problems with assuming that this language is innate and hidden. Included in this section will be a small introduction to the compatibility problem. The compatibility problem offers some obvious difficulties for mentalese theories and these will be discussed. The next stage of the project will focus on evidence that can be put forward in support of the claim that natural language is the language of thought. Our most direct source of evidence comes from introspection, and this will play a dominant role in the discussion. The final part of the thesis will involve an examination of the principle arguments that have been put forward against the idea that natural language is the language of thought. My goal will be to show that these arguments do not entail the existence of mentalese, nor do they show that natural language is not the language of thought. I will provide answers to the arguments, and will explain the phenomena they point to in terms of natural language being the language of thought

    Revealing the language of thought

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    A Deaf Way of Education: Interaction Among Children in a Thai Boarding School

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    This is an ethnographic study of peer society in a boarding school for deaf children in the Kingdom of Thailand. The aim is to describe the students' after-hours interaction together and its function in their intellectual and social development. Deaf children tend to be institutionalized because they are unable to fully participate in the process of socialization conveyed by speech. Deafness is perceived as an inevitable loss to intellectual and social capacity. Considered to be uneducable in ordinary settings, they are sent to residential schools, which remain the predominant placement worldwide. The informal interaction among deaf students has largely been ignored or decried as impeding educational goals. Yet as their first opportunity for unhindered communication, the interaction among deaf students reveals their learning capacity and preferences. Aged six to nineteen years, the youth created educational activities to learn the sign language, in-group and societal norms, and worldly knowledge. They devised a complex social organization via a sign language that is little used or appreciated by teachers. They regulated their modes of interaction with each other according to relative skill in the sign language and mental acuity (a "social hierarchy of the mind"). This provided a pathway of gradually diversifying learning activities. The confinement to a given status group fostered teaching and learning among youth of similar skill levels ( and provided an example of Vygotsky's "zone of proximal development.") Student leadership was split into elders who wielded authority and those few youth who were skilled and creative masters of signs. These "signmasters" were generators of new ideas, storytellers and interpreters. This honored role was aspired to by youngsters, and the skills had been consciously passed down. At the same time there was pressure, by some students and teachers, to supplant creative activities with regimentation. The study recommends that educators examine the overall school environment to assure that there is a "normal" balance of activity that is similar to other children in the society, and to consider the value of deaf students' interactions and sign language as resources in the classroom

    Meeting the Needs of Long-Term English Learners: A Review of the Literature

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    Meeting the Needs of Long-Term English Learners: A Review of the Literatur

    Weakly free regular semigroups I. The general case

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    We prove the existence of a regular semigroup F(X) weakly generated by X such that all other regular semigroups weakly generated by X are homomorphic images of F(X). The semigroup F(X) is introduced by a presentation and the word problem for that presentation is solved.Comment: 23 pages; 4 figure
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