Exercise 4.11 · 习题

Exercise 4.11: Instead of representing a frame

as a pair of lists, we can represent a frame as a list of bindings, where each

binding is a name-value pair. Rewrite the environment operations to use this

alternative representation.

练习 4.11：我们可以将框架表示为绑定的表，而不是表示为两个表组成的序对，其中每个绑定是一个名字-值序对。请重写环境操作以使用这种替代表示。