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

theorem :: REAL_2'48_1
  1 / (a / b) = b / a
proof
  thus 1/(a/b)=1/(a*b") by XCMPLX_0:def 9
    .=(a*b")" by Lm4
    .=b*a" by Lm11
    .=b/a by XCMPLX_0:def 9;
end;
