reserve z,z1,z2,z3,z4 for Element of F_Complex;

theorem Th48:
  z*' = 0.F_Complex implies z = 0.F_Complex
proof
  assume z*' = 0.F_Complex;
  then z*' = 0c by Def1;
  then z = 0c by COMPLEX1:29;
  hence thesis by Def1;
end;
