A \[\varnothing\] B \[R\] C \[\langle - \infty,\; - \frac{1}{2}\rangle U \left[ 3,\; + \infty\right] \] D \[ R - \left\{ \frac{1}{2} \right\}\] E \[\langle - \infty,\; 1\rangle - \langle 3,\; + \infty \rangle\]