Sourdough of chullin that fell into a dough, and it is capable of leavening [the dough], and afterwards sourdough of terumah or sourdough of kilei hakerem fell in, and it is capable of leavening, it is prohibited.

“To be treated [sometimes] leniently and [sometimes] stringently? A type in an unlike type.” How so? For example, where pounded [beans] were cooked with lentils, and they had the capacity to impart flavor, whether they were capable of being nullified in one hundred and one, or whether they were not capable of being nullified in one hundred and one, it is prohibited. If they did not have the capacity to impart flavor, whether they were capable of being nullified in one hundred and one, or whether they were not capable of being nullified in one hundred and one, it is permitted.