Micha Perles

Micha Asher Perles, born in 1936, is an Israeli mathematician who works in geometry and combinatorics and is a professor emeritus at the Hebrew University of Jerusalem. He earned his doctorate at the Hebrew University in 1964 under the supervision of Branko Grünbaum. He is remembered for the Perles configuration, a set of nine points in the plane whose collinearities can only be realized with irrational coordinates, which he used to show that irrational polytopes exist in higher dimensions. His name is also attached to the Perles-Sauer-Shelah lemma in extremal set theory, and he discovered, together with Yehoshua Bar-Hillel and Eli Shamir, the pumping lemma for context-free languages. His students include Noga Alon, Gil Kalai and Nati Linial.