Nedarim 6 - Never mind what I said
Rava said that one needs to spell out everything in a contract or statement, while Abaye says that we understand what is meant. But this is the same as what Rabbi Yehudah and his opponents argued about regarding Get, where Rabbi Yehudah required a full formula of "this is for you the document of removal, etc."
Why would Rava and Abaye, who lived later, argue about the same question? They could just take sides! Rava would be on the side of Rabbi Yehudah, and Abaye - his opponents. No! Abaye will say that even Rabbi Yehudah agrees with him, like so: Rabbi Yehudah required the complete formula only for Get, which should be a complete separate between the husband and wife, but in other cases he too would says that we understand what is meant, exactly as Abaye!
However, later on we find a refutation for Abaye: in another teaching, even in general someone required all the details spelled out, and Abaye had to admit it was Rabbi Yehudah. So how could he previously say that everybody agrees with him, and now - that there are those who disagree!? - Abaye changed his mind and admitted that Rabbi Yehudah was always strict and never agreed to Abaye's point that we understand things from the context.
Here is an interesting question: can one do a vague Kiddushin? That is, can he say to one woman "You are hereby consecrated to me" and to another one - "And you..." Does he mean "And you too" or does he mean "And you should considered the possibility"? This was left unresolved.
Art: Portrait of a Gentleman and his Wife in a Park by John Downman