Boris Abramovich Trakhtenbrot

Boris Abramovich Trakhtenbrot (20.02.1921– 19.09.2016), the centenary of whose birth was celebrated on 20 February 2021, was one of the founders of theoretical computer science, who was widely recognised both in the Soviet Union and all over the world. His scientific biography is also interesting in both its humanistic and historical aspects. He was born on 20 February 1921 in Bessarabia, in the village of Brichevo (which during various periods of time belonged to Russia, Romania, USSR, and Moldova). In 1940 he started studying mathematics at the Kishinev Pedagogical Institute (now Ion Creangă State Pedagogical University). At the beginning of World War II he was evacuated to the Urals with the Institute. By that time Kishinev was already under bombardment. Until 1943 he was completely out of touch with his family, which was separated and deported from Bessarabia to the Urals and Siberia during the large-scale eviction in June of 1941 (paradoxically, this exile saved his family from the Holocaust). Trakhtenbrot was disqualified from active military service because of his weak eyesight. During that period he combined intermittent studies with working at a footwear factory and in a gas trust company. In 1944 he returned from evacuation. For a year he worked as a teacher of mathematics in the town of Beltsy (now Moldovan Bălţi). He completed his mathematical studies at the University of Chernovtsy (now Ukrainian Chernivtsi) in 1945–1947. Parallel to his studies, he took an active part in the restoration of the well-stocked mathematical library of Chernovtsy State University, and this activity played an important role in his education and familiarization with science. A number of teachers at Chernovtsy State University were disciples of Moscow mathematical schools. Among those who had great influence on Trakhtenbrot was A.A. Bobrov, a former student of A. N. Kolmogorov. It was at Bobrov’s seminar on Hausdorff’s monograph that Trakhtenbrot became fascinated by descriptive set theory. On the