Moshe Ya'akov Vardi (Hebrew: משה יעקב ורדי) MAE ForMemRS[5] is an Israeli theoretical computer scientist.He is the Karen Ostrum George Distinguished Service Professor in Computational Engineering at Rice University, United States.He is an expert in model checking, constraint satisfaction and database theory, common knowledge (logic), and theoretical computer science.He has authored the books Reasoning About Knowledge[11] with Ronald Fagin, Joseph Halpern, and Yoram Moses, and Finite Model Theory and Its Applications[12] with Erich Grädel, Phokion G. Kolaitis, Leonid Libkin, Maarten Marx, Joel Spencer, Yde Venema, and Scott Weinstein.[2] He served as chair of the computer science department at Rice University from January 1994 until June 2002.