Suppose someone has a contract that promises to pay an amount each period over a number of years.

假设某人有一份合约,承诺在数年内的不同时段内分开支付

耶鲁公开课 - 金融市场课程节选

You pay every year a fixed amount on your house to the mortgage originator and then after so many-- n is 30 years, typically--you would then have paid it off.

你每年都在你的房子上支付一定数目的偿款,给抵押商然后,数年后,设n是30年,一般来说你已经能偿清贷款了

耶鲁公开课 - 金融市场课程节选