Henry Sheffer was a Polish Jew born in Western Ukraine on 1 September 1888, who emigrated to the United States at the age of four. He was a mathematical logician who proved in 1913 that Boolean Algebra could be defined with a simple binary operation, what is now called the NAND operator.
Lying at the basis of the entire computer industry, he showed that all logical operators can be derived from a single one, NAND. Scheffer introduced what is now known as the Scheffer Stroke in 1913, winning great praise from Bertrand Russell, who used it to greatly simplify his logic in the second edition of Principia Mathematica, published in 1925.