2,652. An Interdependent Condition

Hilchos Shevuos 4:18

Similar to the case in the previous halacha, let’s say that someone made two loaves dependent on one another, taking an oath not to eat one of them if he eats the other. If he forgets his condition and eats one of them, after which he intentionally eats the other, he is liable.

Hilchos Shevuos 4:19

If he ate the first loaf intentionally and the second loaf unintentionally, he’s exempt; if he ate both intentionally, he’s liable.