\begin{align*} &f(x)=x^4+4x+2 \\ &\qquad \{\alpha,\beta,\gamma,\delta\}: \ roots \ of \ f(x)\\ \\ & v: \ Primitive \ element \\ & \qquad v=1\cdot\alpha+2\cdot\beta+3\cdot\gamma+4 \cdot \delta \end{align*}

\[ \qquad The \ system \ of \ equations \]

\[ \left\{ \begin{array}{l} r_1={{\alpha }^{4}}+4\alpha +2=0\\ r_2={{\beta }^{3}}+\alpha {{\beta }^{2}}+{{\alpha }^{2}} \beta +{{\alpha }^{3}}+4=0 \\ r_3={{\gamma }^{2}}+\left( \beta +\alpha \right) \gamma +{{\beta }^{2}}+\alpha \beta +{{\alpha }^{2}}=0\\ r_4= \alpha+\beta+\gamma+\delta =0\\ r_5=v-(\alpha+2\beta+3\gamma+4\delta )=0 \\ \end{array} \right.\\ \quad \\ \qquad \qquad \qquad \Downarrow \]

\[ \qquad Elimination \ Theory \]

\[ V(v)=v^{24}-160v^{20}+5440v^18+30080v^{16}+...\\ \quad...+700091596800v^2+4691625312256\\ \]

\begin{align*} &V(x): \ irreducible \ polynomial \\ \\ &\therefore \ g_0(x) \equiv V(x) \qquad deg(g_0(x))=24\\ \\ &g_0(x):minimal \ polynomial \ of \ v \ on \ F_0=Q(\omega) \\ \end{align*}

\[Factorization \ of \ f(x) \ on \ F_0(v)\] \[\quad "maxima's \ function \ "\] \[\qquad factor(f(x),g_0(v))\]

\begin{align*} &\alpha=\alpha(v), \ \beta=\beta(v), \ \gamma=\gamma(v), \ \delta=\delta(v)\\ \\ &roots \ of \ g_0(x) \ ( \ =V(x) \ )\\ &\quad [ \ v_1=v_1(v), \ ....\ , \ v_{24}=v_{24}(v) \ ] \\ \end{align*}

\begin{align*} &S_4: Galois \ group \ of \ f(x) \\ &composition \ series \quad S_4 \rhd \ A_4 \rhd \ V_4 \rhd \{e\} \end{align*}

\[g_1(x)\ : \ minimal \ polynomial \ of \ v\\ \qquad g_1(x) \ \in \ F_0(a_1)[x]\qquad deg(g_1(x))=12 \\ \quad \\ B_1=a_1^2+17510400\]

\[g_2(x)\ : \ minimal \ polynomial \ of \ v\\ \qquad g_2(x) \ \in \ F_1(a_2)[x] \qquad deg(g_2(x))=4\\ \quad \\ B_2=a_2^3-\frac{14 {a_1} \omega }{27}-2304 \omega -\frac{89 {a_1}}{135}+1088 \]

\[ g_3(x)\ : \ minimal \ polynomial \ of \ v\\ \qquad g_3(x) \ \in \ F_2(a_3)[x] \qquad deg(g_3(x))=2\\ \]

\[ B_3=a_3^2-\biggl( \frac{23 {a_1} {{a}_{2}^{2}} \omega }{324480}+\frac{63 {{a}_{2}^{2}} \omega }{338}-\frac{8 {a_2} \omega }{13}\\ \qquad \qquad +\frac{{a_1} {{a}_{2}^{2}}}{324480}+\frac{135 {{a}_{2}^{2}}}{338}-\frac{32 {a_2}}{13} \biggr)\\ \]

\[ g_4(x)\ : \ minimal \ polynomial \ of \ v\\ \qquad g_4(x) \ \in \ F_3(a_4)[x] \qquad deg(g_4(x))=1\\ \]

\[ B_4=a_4^2-\biggl(-\frac{11 {a_1} {{a}_{2}^{2}} \omega }{2595840}+\frac{9 {{a}_{2}^{2}} \omega }{676}+\frac{2 {a_2} \omega }{13} \\ \qquad \qquad -\frac{23 {a_1} {{a}_{2}^{2}}}{5191680}-\frac{63 {{a}_{2}^{2}}}{5408}+\frac{3 {a_2}}{26}\biggr)\\ \]

\begin{align*} &v=v(a_1,a_2,a_3,a_4,\omega) \ \in \ F_4=F_0(a_1,a_2,a_3,a_4,\omega) \\ \\ &\left\{ \begin{array}{l} \alpha=\alpha(a_1,a_2,a_3,a_4,\omega), \ \ \beta=\beta(a_1,a_2,a_3,a_4,\omega) \\ \gamma=\gamma(a_1,a_2,a_3,a_4,\omega), \ \ \delta=\delta(a_1,a_2,a_3,a_4,\omega) \\ \end{array} \right.\\ \end{align*}