To argue validly that, given that if p then q and given not-q, we can infer not-p. ‘If the leg is broken this will hurt; it does not hurt, so the leg is not broken.’
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。