reserve a, b, c, d, e for Complex;

theorem
  b <> 0 implies a = a*b*b"
proof
A1: a*(b*b") = a*b*b";
  assume b <> 0;
  then a*1 = a*b*b" by A1,XCMPLX_0:def 7;
  hence thesis;
end;
