From: Rabbi Moshe Sofer
To: Rabbi Zelig
Rabbi Zelig proposes that the Talmudic opinion not requiring 'din mamon' for esrog validity effectively eliminates the 'lachem' (yours) requirement entirely. The Chasam Sofer firmly rejects this, clarifying that both opinions require lachem but disagree on what constitutes it.
Source: Shu"t Chasam Sofer OC §179