noun
one-to-one correspondence
Mathematical term for a bijection between two sets, where each element of one set is paired with exactly one element of the other set.
自然数と偶数の間には一対一対応が存在する。
There is a one-to-one correspondence between the natural numbers and the even numbers.
全単射 (bijection) is a more formal mathematical synonym, while 一対一対応 is often used in educational contexts.
Compound of 一対一 (one-to-one) and 対応 (correspondence).