In a recent [Quanta article](https://www.quantamagazine.org/ninth-dedekind-number-found-by-two-independent-groups-20230801/) about the 9th Dedekind number, Dedekind is credited with the first formal definition of infinity.

>Is this an accurate attribution?

Folklore where I’m from dictates that Georg Cantor is the father of modern infinity, but they were alive and working concurrently and I’m not familiar enough with either mathematician’s body of work to pin down when he first proposed a formal definition of infinity. Any assistance is appreciated.