Beitzah 4A

אומר: רואין את העליונות כאלו הן פרודות, והתחתונות מעלות את העליונות.

says: One considers the upper circles of dried figs as though they are separate pieces, rather than one unit. And the lower ones, which were there beforehand and have certainly been tithed, nullify the upper ones, as there are enough circles of figs in the entire jug to nullify the upper litra.

רבי יהושע אומר: אם יש שם מאה פומין ⁠— יעלו, ואם לאו ⁠— הפומין אסורין, והשולים מותרין.

In contrast, R' Yehoshua says: If there are 100 mouths of different jugs or circular vessels there, the prohibited litra of untithed figs on the mouth of one of the vessels is nullified by a ratio of one part of prohibited figs to 100 parts of similar, permitted figs. And if not, all of the circles of figs at the mouths of the jugs or circular vessels are prohibited, as one of them clearly contains a prohibited litra that has not been nullified. And the figs on the insides of the vessels are permitted, as the prohibited figs certainly did not reach there. This is R' Meir’s version of the dispute.

רבי יהודה אומר, רבי אליעזר אומר: אם יש שם מאה פומין ⁠— יעלו, ואם לאו ⁠— הפומין אסורין, והשולים מותרין. רבי יהושע אומר: אפילו יש שם שלש מאות פומין ⁠— לא יעלו.

R' Yehuda says a different version of the dispute. R' Eliezer says: If there are 100 mouths of vessels with permitted figs present there, in addition to the prohibited one, it is nullified by the 100 permitted mouths. And if not, the figs at the mouths are prohibited and those at the bottom are permitted. R' Yehoshua says: Even if there are 300 mouths present there, they are not nullified, as this litra cannot be nullified in any manner. Rav Pappa was referring to this opinion when he said that there is a tanna, meaning R' Yehoshua in R' Yehuda’s version, who maintains that even an item occasionally sold by unit, e.g., a circle of dried figs, can never be nullified.