bijektiivisessä
The Finnish word "bijektiivisessä" is the inessive case of the word "bijektiivinen". "Bijektiivinen" is the Finnish translation for the mathematical term "bijective". A bijective function, also known as a bijection or one-to-one correspondence, is a function that is both injective (one-to-one) and surjective (onto).
In more detail, a function f from a set A to a set B is injective if
A function f from a set A to a set B is surjective if for every element
Therefore, a bijective function is one where each element in the domain maps to a unique element