If one learns lemaskana that R Yehudah in Braisah (50b) argues with mishnah on 51a, or according to hava amennah that this is so, is R Yehudah's din that a seller has upper hand and thus may be chozer on the transaction a din min hatorh or midirbannon? Either way, what is the reason to afford only the seller this advantage? On 51a the gmara discusses a different advantage afforded to sellers of the sirsor category - they even less than one-sixth they can be chozer, which Rashi explains is due to their livelihood. This reason was not applied to the din of one-sixth, so the answer to this question would appear to need to be different than that.

Daniel Gray, TORONTO Canada