Whether the appellant's letter constituted a withdrawal under Art. 241 CPC and rendered the appeal moot.
Yes. The court treated the letter as a unilateral withdrawal of the action, which ended the proceedings and made the appeal moot.
Art. 241 al. 2 CPC lists withdrawal as a way to end proceedings without a decision. The appellant expressly renounced the provisional and superprovisional mortgage-registration proceedings before the prior dispositive had entered into force, so the appeal had become moot.