How does -7 % 3 = 2, -13 % 3 = 2 or -1 % 3 = 2 exactly behaves under the hood? Ruby

Question

I was curious what is the formula for negative number % positive number or vice versa. Ruby

-7 % 3 = 2

-13 % 3 = 2

-1 % 3 = 2