Questão jurídica principal
Whether the signed payment undertaking was a cumulative debt assumption or a suretyship
Decisão extraída
The undertaking was to be construed as a suretyship, not as a cumulative debt assumption.
Fundamentação extraída
The wording of the form, the lack of a clear own economic interest, and the overall context did not objectively show an intention to create an independent debt. As a layperson, the respondent could understand the text as a guarantee for the father's obligations.