In mathematics, derivators are a proposed new framework for homological algebra and various generalisations. It is intended to address the perceived deficiencies of derived categories and provide at the same time a language for homotopical algebra.
英汉双解词典包含3185865条英汉词条，基本涵盖了全部常用单词的翻译及用法，是英语学习的有利工具。