axiom of restriction

…ZF by adding a “foundation axiom,” which explicitly prohibited sets that contain themselves as members. In the 1920s and ’30s, von Neumann, the Swiss mathematician Paul Isaak Bernays, and the Austrian-born logician Kurt Gödel (1906–78) provided additional technical modifications, resulting in what is now known as von Neumann-Bernays-Gödel set

…Neumann of axiom 10, the axiom of restriction, or foundation axiom.