const In : set set prop term iIn = In infix iIn 2000 2000 const real : set const CSNo_Im : set set const SNo_pair : set set set axiom complex_Im_eq: !x:set.x iIn real -> !y:set.y iIn real -> CSNo_Im (SNo_pair x y) = y const complex : set axiom complex_E: !x:set.x iIn complex -> !P:prop.(!y:set.y iIn real -> !z:set.z iIn real -> x = SNo_pair y z -> P) -> P claim !x:set.x iIn complex -> CSNo_Im x iIn real