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

theorem :: REAL_2'61_1
  a / (b / c) = a * (c / b)
proof
  thus a/(b/c)=(a*c)/b by Lm2
    .=a*c*b" by XCMPLX_0:def 9
    .=a*(c*b")
    .=a*(c/b) by XCMPLX_0:def 9;
end;
