
theorem Th6:
  for x1,y1 be Element of F_Complex for x2,y2 be Complex st
  x1 = x2 & y1 = y2 & y1 <> 0.F_Complex holds x1/y1 = x2/y2
proof
  let x1,y1 be Element of F_Complex;
  let x2,y2 be Complex;
  assume that
A1: x1 = x2 and
A2: y1 = y2;
  assume y1 <> 0.F_Complex;
  then y1" = y2" by A2,Th5;
  hence thesis by A1,XCMPLX_0:def 9;
end;
