2 For each Loan, endDate >= issueDate
3 For each Loan, finePaidDate >= returnDate
* Membership.nrOnLoanItems = count each Loan that was issued to Membership
and was returned on no Date
* Loan is overdue by Period iff Loan ended on no Date
and Period = today - Loan.issueDate - Loan.issueDate.year.normalLoanPeriod
and Period > 0
* Loan.unpaidFine = Loan.overduePeriod.nrUnits * Loan.issueDate.year.dailyLateFee
* Loan.paidFine = (Loan.returnDate - Loan.issueDate - Loan.returnDate.year.normalLoanPeriod).nrUnits
* Loan.returnDate.year.dailyLateFee