They define four credit risk categories and they define a formula involving the amount of assets in each of the categories.

他们定义了四个风险等级,然后根据每个风险等级下的资产额,定义了一个资产总额的计算公式

耶鲁公开课 - 金融市场课程节选

Then there's Tier II capital and then they have a formula -now, this is defined in Fabozzi.

然后又有了二级资本金,他们对此有个计算公式,如今,这在法博齐的书中有定义

耶鲁公开课 - 金融市场课程节选