Bava Batra 142: The Fetus Does Not Inherit

More on the powers of acquisition (or lack thereof) of a fetus. What is the timing of a person trying to bequeath property to a fetus, when that person than dies? And most importantly, what changes once the baby is born and is only one day old? Also, given the conclusion that a fetus cannot inherit, the Gemara's focus shifts to the nature of the dispute and the hierarchy of the sages responding (including pinning authority to age-order, at least briefly).