There is no flag in the ar open file to set a fully paid status as you can reapply documents at any time until they are purged. If amt 1 + amt 2 are applied equally to a document with an opposite sign such as CM or PMT, then the document doesn't show as open. If you really want to dig into the formulas, check the ICR for ARAGERPT. There are about 50 formulas in there you can borrow or maybe you can modify the ICR to do what you want.