Calculus, developed by Newton and Leibniz, is based on derivatives and integrals of curves.
演算，由牛顿和莱布尼茨的，是基于对衍生工具和积分的曲线。
2
Based on this model, this paper constructs two different kinds of medium relational database query languages: medium relational calculus and medium relational algebra.
Based on the relational knowledge model, the knowledge base management system GKBMS is introduced in this paper. GKBMS combines predicate calculus with relational calculus.