Indicator function question

[sladja]

Hello,

I have a question about indicator functions. I have a variable b_t in the model which can denote borrowing, if positive, and retained earnings if negative. The saving rate is r_st=r_ft-k, wher r_ft is the borrowing rate. I have that:
, where .

I am not sure if this is modelled as a standard indicator function? Thank you for your help.

[jpfeifer]

Yes, an indicator function like that would work.

[sladja]

Thank you!