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

theorem Th81: :: REAL_2'61_3
  a / (b / e) = e * (a / b)
proof
  thus a/(b/e)=(a*e)/b by Lm2
    .=e*a*b" by XCMPLX_0:def 9
    .=e*(a*b")
    .=e*(a/b) by XCMPLX_0:def 9;
end;
