The article is devoted to a particular form of freedom of assembly — the right to counter-demonstrate. The author underlines the value of this right as an element of democratic society, but also acknowledges the risk of violent actions among participants of opposing demonstrations. Due to this risk, the government may adopt adequate measures restricting the right to counter-demonstrate, certain types of which are analyzed in this paper.
An initial–boundary value problem for the generalized Schrödinger equation in a semi-infinite strip is solved.
A new family of two level finite-difference schemes with averaging over spatial variables on a finite mesh is constructed, which covers a set of finite-difference schemes built using various methods. For the family, an abstract approximate transparent boundary condition (TBC) is formulated and the solutions are proved to be absolutely stable in two norms with respect to both initial data and free terms. A discrete TBC is derived, and the stability of the family of schemes with this TBC is proved. The implementation of schemes with the discrete TBC is discussed.