It is known (see [1, 3.1.5]) that the order type of the nonstandard natural number system * N has the form ω + (ω * + ω) θ, where θ is a dense order type without first or last element and ω is the order type of N. Concerning this, Zakon [2] examined * N more closely and investigated the nonstandard real number system * R, as an ordered set, as an additive group and as a uniform space. He raised (...) five questions which remained unsolved. These questions are concerned with the cofinality and coinitiality of θ (which depend on the underlying nonstandard universe * U). In this paper, we shall treat nonstandard models where the cofinality and coinitiality of θ coincide with some appropriated cardinals. Using these nonstandard models, we shall give answers to three of these questions and partial answers to the other to questions in [2]. (shrink)

The aim of this paper is to restore the interdependent or complementary relationship between self and others against the universalistic one (as I call it) that Kant, for example, once insisted on, by reexamining the concept of so-called private language. I shall consider some views in speech act theory and pragmatics, since there has often been discussion about such a private occurrence as the speaker's sincerity. For example, Jürgen Habermas situates it in the speaker's internal nature as will be seen (...) later. In my opinion, alter ego is an ego because we can empathize (einfühlen) with it, and yet it is alter ego because it has some private experiences which we cannot perfectly comprehend. (shrink)

For ${b \in {^{\omega}}{\omega}}$ , let ${\mathfrak{c}^{\exists}_{b, 1}}$ be the minimal number of functions (or slaloms with width 1) to catch every functions below b in infinitely many positions. In this paper, by using the technique of forcing, we construct a generic model in which there are many coefficients ${\mathfrak{c}^{\exists}_{{b_\alpha}, 1}}$ with pairwise different values. In particular, under the assumption that a weakly inaccessible cardinal exists, we can construct a generic model in which there are continuum many coefficients ${\mathfrak{c}^{\exists}_{{b_\alpha}, 1}}$ (...) with pairwise different values. In conjunction with these results, we give a generic model in which there are many Yorioka’s ideals ${\mathcal{I}_{f_\alpha}}$ with pairwise different covering numbers. (shrink)

本研究は、史料的裏付けにもとづく、東アジア三地域における気の思想・文化の歴史や内容、特徴を明らかにし、東アジアにおける気の総合的・体系的研究の基礎を構築している。.

In 2002, Yorioka introduced the σ-ideal ${{\mathcal {I}}_f}$ for strictly increasing functions f from ω into ω to analyze the cofinality of the strong measure zero ideal. For each f, we study the cardinal coefficients (the additivity, covering number, uniformity and cofinality) of ${{\mathcal {I}}_f}$.