Whether the daughter could be ordered to sign a new mortgage contract under the donation/usufruct arrangement or the law.
No enforceable duty to contract existed; neither the donation deed nor the law required the daughter to sign a new mortgage agreement.
The donation deed only bound her to the existing mortgage debt, not to future credits. Art. 765 CC made the usufructuary liable for passiver interest but did not authorize forcing the bare owner to change the mortgage regime. No analogous duty arose from usufruct law or from any objective norm of conduct.