Mariko Yasugi

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We speculate on logical aspects of the so-called three wise men puzzle with proof-theoretic methods. We propose and study the following. (1) Logical ability of each player of a puzzle is equivalent to a logical system KL, which is based on classical propositional calculus augmented with inferences of knowledge operators. (2) Enriched pieces of knowledge of(More)
We consider an abstract metric space with a computuhility structure and an e$%ctive separating .wt. In this article, we also introduce an @stiffly a-compuct spuce. The computability of real-valued functions on such a space is defined. It is shown that some of typical propositions in a metric space, namely Baire category theorem, Tietze’s extension theorem(More)
In this article, we discuss the Fine computability and the effective Fine convergence for functions on [0, 1) with respect to the Fine metric as the beginning of the effective Walsh-Fourier analysis. First we treat classically the Fine continuity and the Fine convergence. Next, we prove that Fine computability does not depend on the choice of an effective(More)
We consider real sequences in I = [0, 1) and real functions on I . It is first shown that, as for real sequences from I , R-computability (computability with respect to the Euclidean topology) implies “weak Fine-computability.” Using this result, we show that “Fine-sequential computability” and “L∗-sequential computability” are equivalent for effectively(More)