const In : set set prop term iIn = In infix iIn 2000 2000 const complex : set const CSNo : set prop axiom complex_CSNo: !x:set.x iIn complex -> CSNo x const CSNo_Re : set set const CSNo_Im : set set axiom CSNo_ReIm_split: !x:set.!y:set.CSNo x -> CSNo y -> CSNo_Re x = CSNo_Re y -> CSNo_Im x = CSNo_Im y -> x = y claim !x:set.x iIn complex -> !y:set.y iIn complex -> CSNo_Re x = CSNo_Re y -> CSNo_Im x = CSNo_Im y -> x = y