Exercise 2.80 · 习题

Exercise 2.80: Define a generic predicate

=zero? that tests if its argument is zero, and install it in the generic

arithmetic package. This operation should work for ordinary numbers, rational

numbers, and complex numbers.

练习 2.80：定义一个通用谓词 =zero?，用于检验其参数是否为零，并将其安装到通用算术包中。该操作应适用于普通数、有理数和复数。