[If] a seah of terumah fell into one hundred [seahs of chullin], and he then milled them and they diminished, just as the chullin diminished, so did the terumah diminish, and it is permitted.  [If] a seah of terumah fell into less than one hundred [seahs of chullin], and he milled them [together], and they increased, just as the chullin increased so did the terumah increase, and it is forbidden. [But] if it is known that the chullin wheat is of a higher grade than that of the terumah, it is permitted. [If] a seah of terumah fell into less than one hundred [seahs of chullin], and afterwards [more] chullin fell there, if it was inadvertent, it is permitted; but if it was intentional, it is forbidden.