A relation is reflexive in a domain if everything in the domain bears it to itself: (∀x)Rxx. Identity and relations couched in terms of identity are reflexive: everyone is the same height, weight, etc. as him or herself.
科学参考收录了60776条科技类词条，基本涵盖了常见科技类参考文献及英语词汇的翻译，是科学学习和研究的有利工具。