Of course, you've got to be a little careful when you use it.

当然,使用公式时也要小心点儿

耶鲁公开课 - 基础物理课程节选

Notation: so I'm going to use little "si" to be a particular strategy of Player i.

表述法,我们用小写si来表示参与人i的某个策略

耶鲁公开课 - 博弈论课程节选