Zevahim 100: When a Kohen Mourns

Rabbi Shimon's position of the acute mourner and the Pesach offering - and ways of resolving the apparent contradictions in his respective positions. Specifically, must the kohen become impure for the death of a close relative or does he have permission to do so? A clear dispute. But the need for a "met mitzvah" - perhaps that is not disputed, and the kohen must become impure for the sake of that need to bury. Also, a deeper dive into the view that says the acutely mourning kohen must partake of the Pesach offering.