Three temporal logics i. e. first-orderpredicate calculus, modal logic and reified logic are discussed.
讨论了三种时间逻辑方法：一阶谓词演算，模态逻辑及具体化逻辑。
2
This kind of assertion seems to require special language extensions and has led people to suggest introducing first-orderpredicate calculus.
这种情况下的断言似乎就需要实现特定的语言扩展，于是一些人建议引入一阶谓词演算。
3
Informally, XQuery is designed to be able to construct any XML document that can be computed from input XML documents using the power of the first-orderpredicate calculus.