 He is considered to be one of the founders of what is today known as algorithmic (Solomonoff-Kolmogorov-Chaitin, Kolmogorov or program-size) complexity together with Andrei Kolmogorov and Ray Solomonoff.Along with the works of e.g.Solomonoff, Kolmogorov, Martin-Löf, and Leonid Levin, algorithmic information theory became a foundational part of theoretical computer science, information theory, and mathematical logic.