\[ y^{(4)}(x)=0 \] ✓ Mathematica : cpu = 0.003467 (sec), leaf count = 24
\[\left \{\left \{y(x)\to c_4 x^3+c_3 x^2+c_2 x+c_1\right \}\right \}\] ✓ Maple : cpu = 0.018 (sec), leaf count = 21
\[\left \{y \left (x \right ) = \frac {1}{6} c_{1} x^{3}+\frac {1}{2} c_{2} x^{2}+c_{3} x +c_{4}\right \}\]