I read several articles about mathematical logic these days. Finally, I just found some work done by Boris. Record the intro here.
Boris (Boaz) Avraamovich Trakhtenbrot (Russian: Борис Авраамович Трахтенброт; 19 February 1921 – 19 September 2016), or Boaz (Boris) Trakhtenbrot (Hebrew: בועז טרכטנברוט) was an Israeli and Russian mathematician in mathematical logic, algorithms, theory of computation, and cybernetics. Trakhtenbrot was born in Brichevo, northern Bessarabia. He worked at Akademgorodok, Novosibirsk during the 1960s and 1970s. After immigrating to Israel in 1981, he became a professor in the faculty of Exact sciences of Tel Aviv University, where he was professor emeritus until his death.
In 1964 Trakhtenbrot discovered and proved a fundamental result in theoretical computer science called the Gap theorem. He also discovered and proved what is now called Trakhtenbrot’s theorem which is a theorem in logic, model theory, and computability theory. He died on 19 September 2016, aged 95.