инфинитезимальный
infinitesimal matrix инфинитезимальная матрица
infinitesimal operator инфинитезимальный оператор
infinitesimal system of measures инфинитезимальная система мер
English-Russian Dictionary on Probability, Statistics, and Combinatorics. — Philadelphia and Moscow. Society for Industrial and Applied Mathematics and TVP Science Publishers. K. A. Borovkov. 1994.