English: The Wigner function for tunneling through the potential barrier ${\displaystyle U(x)=8e^{-0.25x^{2}}}$ in atomic units (a.u.). The solid lines represent the level set of the Hamiltonian ${\displaystyle H(x,p)=p^{2}/2+U(x)}$. The Wigner's function normalization is ${\displaystyle \int dxdp\,|W(x,p)|^{2}=1}$ during the entire evolution.