please review my understanding and questions:
rav huna's din: the psul in the mishna is the case where there is NO one-tefach hole within the 7x7 area.
if there is such a one tefach hole, an ohel exists (rashi), and we can raise the height of the walls up to ten tef.
1. our mishna prohibits a succah which was burrowed from a haystack.
2. we have a beraisa that permits a succah burrowed from a haystack.
rav huna resolves the contradiction between the mishnah and the beraisa by stating that the beraisa is discussing a case where the one tefach space exists.
others learn rav huna as resolving the conreadiction between the mishna and beraisa.
what's the difference between the first limud and others learn?
in the others limud, rav huna appears after the contradiction between the mishna and the beraisa. in the first limud, rav huna leads off the discussion and the contradiction between the mishna follows.
what's going on? please enlighten me in plain english.
This format is found countless times in Shas. There is no essential difference other than the accuracy of how the words of Rav Huna were transmitted in the Beis Midrash. The first version quoted Rav Huna as having qualified the Mishnah. The Mishnah wrote that one may not dig out a haystack in order to create a Sukah, and Rav Huna qualified this by limiting the Mishnah to a case where there was not an existing airspace of a Tefach height. According to this version the Beraisa is brought as a support to Rav Huna, for the fact that we have a contradiction between the Mishnah and the Beraisa proves that neither is universal, but rather that they both must be limited to different cases. This in turn supports the quotation from Rav Huna who actually qualified the Mishnah.
The second version is essentially the same in content, except that Rav Huna was quoted as having said his qualification of the Mishnah as a suggestion to deal with the contradiction.
There can be a difference between the two versions. In the first version, Rav Huna's statement was absolute. In other words, even if we were to reconcile the contradiction in another fashion (such as discovering that they had different authors), Rav Huna's opinion remains that the Mishnah is only referring to where there was no Tefach of airspace. This determination was not based on the contradiction, but rather on other objective reasoning. However, in the second version, Rav Huna was suggesting an answer to the contradiction; it is possible that if we were to find that the Beraisa was mistakenly transcribed, the Mishnah would revert to being absolute.