Lexicographic sums and fibre-faithful maps |
| |
Authors: | Reinhard Börger Walter Tholen Anna Tozzi |
| |
Affiliation: | (1) Fb. Mathematik u. Informatik, Fernuniversität, W 5800 Hagen, Germany;(2) Department of Mathematics & Statistics, York University, M3J 1P3 North York, Canada;(3) Dipartimento di Matematica Pura ed Appl., Università, 67100 L'Aquila, Italy |
| |
Abstract: | The notion of lexicographic sum is introduced in general categories. Existence criteria are derived, particularly for locally cartesian closed categories and for categories with suitable coproducts. Lexicographic sums satisfy a generalized associative law. More importantly, every morphism can be factored through the lexicographic sum of its fibres. This factorization and the two types of maps arising from it, fibre-trivial and fibre-faithful, are studied particularly for partially ordered sets and forT1-spaces. |
| |
Keywords: | 18A30 18A32 18D10 54B30 06A99 |
本文献已被 SpringerLink 等数据库收录! |
|