From: Rabbi Akiva Eiger
To: Rabbi Moshe Eiger
Rabbi Akiva Eiger responds to his father's question about why the Gemara in Shabbos 4b uses the tentative word "dilma" (perhaps) if the conclusion regarding hanacha is meant to be certain. He offers two approaches: a simple answer that the proof only establishes a general distinction without specifying the makom arba requirement, and a deeper argument that "dilma" functions not as doubt but as the establishment of a necessary logical premise that enables a subsequent certain proof regarding akirah. He notes that the Rashba raised the identical question.
Source: Shu"t Rabbi Akiva Eiger §157