const In : set set prop term iIn = In infix iIn 2000 2000 term nIn = \x:set.\y:set.~ x iIn y const Empty : set axiom EmptyE: !x:set.nIn x Empty axiom FalseE: ~ False const SNo : set prop const SNoCutP : set set prop axiom SNoCutP_L_0: !x:set.(!y:set.y iIn x -> SNo y) -> SNoCutP x Empty claim SNoCutP Empty Empty