library.loans@$l#$il.books@$b#$ib[$l.isbn=$b.isbn]#$ib2.customers@$c#$ic[$l.customer=$c.id].{
  'title': $b.title,
  'customer': $l.customer,
  'name': $c.name,
  'loan-index': $il,
  'book-index': $ib,
  'customer-index': $ic,
  'ib2': $ib2
}