BT BM 18b(13) :ר׳ זירא רמי מתני׳ אבריתא ומשני‏ : PN raises a contradtiction between our mishna and the baraita, and resolves it
See the entire entry for rmy vb. to throw; put down

BT BM 18b(13) :ר׳ זירא רמי מתני׳ אבריתא ומשני דלא ניהדר‏ : PN puts the mishna against the baratia and resolves the contradiction: he should not return it
See the entire entry for šny vb. to be different