[IDEM libro uicensimo octauo ad edictum. ] §16.2.7.prQuod in diem debetur, non compensabitur, antequam dies uenit, quamquam dari oporteat.
[THE SAME, On the Edict, Book XXVIII.] What is owed with a future due date will not be set off before the day arrives, although it ought to be given.
§16.2.7.1Si rationem compensationis iudex non habuerit, salua manet petitio: nec enim rei iudicatae exceptio obici potest.
If the judge does not take account of the set-off, the claim remains intact; for the exception of res judicata cannot be raised.
aliud dicam, si reprobauit pensationem quasi non existente debito: tunc enim rei iudicatae mihi nocebit exceptio.
I would say otherwise if he rejected the set-off on the ground that the debt does not exist; for then the exception of res judicata will prejudice me.