So you are trying, I like that.

1- You cannot compare a number like payment_term with a date like payment_date.
The first term of your predicate should be a date like (loan_date + payment_term)

2- You can't substract a date like loan_date from a varchar like loan_type; actually not sure why you added that "- l.loan_date" at the end of your predicate, just take it away.

You are almost there.