A peculiar property of this is that the mortgage balance falls slowly at first and then it gradually picks up; it's just a property of this formula.

其中一个特别的性质是,刚开始抵押贷款余额降得很慢,渐渐的,越降越快,这就是这个公式的性质

耶鲁公开课 - 金融市场课程节选

It's very important to understand that the mortgage balance is recomputed, according to this formula every month and they will send you a statement showing how your mortgage balance is falling.

根据这个公式 抵押贷款余额,每个月都要重新计算,理解这一点非常重要,他们会给你寄对账单,告诉你抵押贷款余额减少的情况

耶鲁公开课 - 金融市场课程节选