This note deals with some classes of bounded subsets in a quasi-metric space. We study and compare the bounded sets, totally-bounded sets and the Bourbaki-bounded sets on quasi metric spaces. For example, we show that...This note deals with some classes of bounded subsets in a quasi-metric space. We study and compare the bounded sets, totally-bounded sets and the Bourbaki-bounded sets on quasi metric spaces. For example, we show that in a quasi-metric space, a set may be bounded but not totally bounded. In addition, we investigate their bornologies as well as their relationships with each other. For example, given a compatible quasi-metric, we intend to give some necessary and sufficient conditions for which a quasi metric bornology coincides with the bornology of totally bounded sets, the bornology of bourbaki bounded sets and bornology of bourbaki bounded subsets.展开更多
In this paper the importance of eometry?and raphics?for the advancement of science and knowledge in 19th century is pointed out. Klein and Müller reform of geometry syllabus in 19th century and the education situ...In this paper the importance of eometry?and raphics?for the advancement of science and knowledge in 19th century is pointed out. Klein and Müller reform of geometry syllabus in 19th century and the education situation of Geometry and Graphics in Europe during the last third of 20th century are introduced. The problems of geometry and graphics education during the next decedes and six proposals are presented.展开更多
文摘This note deals with some classes of bounded subsets in a quasi-metric space. We study and compare the bounded sets, totally-bounded sets and the Bourbaki-bounded sets on quasi metric spaces. For example, we show that in a quasi-metric space, a set may be bounded but not totally bounded. In addition, we investigate their bornologies as well as their relationships with each other. For example, given a compatible quasi-metric, we intend to give some necessary and sufficient conditions for which a quasi metric bornology coincides with the bornology of totally bounded sets, the bornology of bourbaki bounded sets and bornology of bourbaki bounded subsets.
文摘In this paper the importance of eometry?and raphics?for the advancement of science and knowledge in 19th century is pointed out. Klein and Müller reform of geometry syllabus in 19th century and the education situation of Geometry and Graphics in Europe during the last third of 20th century are introduced. The problems of geometry and graphics education during the next decedes and six proposals are presented.