In proof theory, a property holding of a sequent calculus when for every cut free proof, any formula that appears in a cedent in the proof appears as a subformula of some formula appearing in the final sequent.
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。