Review and Monday's shiur

A summary of where we are holding to date:

Last week's abbreviated schedule brought the following conclusions:

a) The Gemara's inference that the (forbidden) removal of the berries on Yom Tov still produce a kosher hadas, is based on the fact that the action is forbidden in the first place. As the Aruch L'ner explains, the only reason that berry-removal is not allowed on Yom Tov is that it's a productive act, producing a כלי/vessel, according to the sages.  The over-berried myrtle is transformed into a kosher hadas.  If so, it MUST BE that the berry removal (even on YT) makes it kosher - otherwise, what's the problem in the first place?

b) Given the above, the Gemara attempts to define the fact situation of the mishna: what was  the status of the hadas going into Yom Tov?

Possibility #1: It had black berries prior to Yom Tov.  

Conclusion: If so, this is a case of דיחוי מעיקרא - and the mishna thus seems to be ruling that disqualification from the outset can be reversed: דיחוי מעיקרא לא הוי דיחוי

This, then seems to answer at least a part of R. Yirmiya's initial question - and seemingly his נקטם ראשו case!  Why, then, did he not see this in the mishna? This is what the Gemara appears to mean when it says תפשוט מינה etc

Possibility #2: It developed the black berries only on Yom Tov.  When Yom Tov began, it had green berries that only later turned black.

Conclusion: This, however, seems to be a case of נראה ונדחה - and the mishna would then be ruling that such a case can rectify itself - חוזר ונראה.  This is a problem for R. Yirmiya as well: If the halacha makes נראה ונדחה kosher, then it would make דיחוי מעיקרא kosher, as well, based on a Kal V'chomer: If a situation which, it could be argued - should not be kosher, is kosher, how much moreso a situation that is more lenient...

As applied here: A hadas that was rejected - can become kosher again when the berries are removed.  How much moreso a hadas that was never rejected!

If so, R. Yirmiya should have seen an answer to his question in the mishna!

Possibility #3 - same as #1:
So - the Gemara returns to the first suggestion - that the berries were black going into Yom tov.  Why? When it comes to a lesson to be learned from a mishna - we learn the lesser "chiddush" - we don't presume that the halacha is more far-reaching that it is.  We therefore only have permission to read the mishna as validating the principle of דיחוי מעיקרא לא הוי דיחוי, and not the principle of נראה ונדחה חוזר ונראה.

Still left unsolved: Why R. Yirmiya did not see an answer to his question from this mishna!!!