实现了函数依赖集的闭包和正则覆盖输入为一个函数依赖 输出它的函数依赖集的闭包及一个函数依赖集 数据库Achieve closure of functional dependencies and regular coverage of the input is a function dependent on the output of its closure of functional dependencies and a set of functional dependencies database-Achieve closure of functional dependencies and regular coverage of the input is a function dependent on the output of its closure of functional dependencies and a set of functional dependencies database