Questão jurídica principal
Whether a non-opposed payment order can prove extinction of a debt by set-off under Art. 85 LP.
Decisão extraída
No. A payment order that was not opposed has only enforcement-law effects and does not prove, by title, the existence of the counterclaim or the extinction of the debt by set-off.
Fundamentação extraída
Art. 85 LP requires proof by title of extinction of the debt. Non-opposition to a payment order does not affect substantive law and does not amount to a debt acknowledgement. At most it enables continuation of that enforcement, so it cannot serve as proof of extinction by compensation in a different proceeding.