\[ y'(x) (-\sin (y(x))+x \sin (x y(x))+\cos (y(x)+x))+y(x) \sin (x y(x))+\cos (y(x)+x)+\cos (x)=0 \] ✓ Mathematica : cpu = 0.630828 (sec), leaf count = 31
\[\text {Solve}[\cos (y(x))-\cos (x y(x))+\sin (x) \cos (y(x))+\cos (x) \sin (y(x))+\sin (x)=c_1,y(x)]\] ✓ Maple : cpu = 0.174 (sec), leaf count = 22
\[ \left \{ -\cos \left ( xy \left ( x \right ) \right ) +\sin \left ( x \right ) +\sin \left ( y \left ( x \right ) +x \right ) +\cos \left ( y \left ( x \right ) \right ) +{\it \_C1}=0 \right \} \]