Mixed problem

A problem involving (systems of) partial differential equations, with initial conditions and boundary conditions, and also problems with data on both characteristic and non-characteristic oriented manifolds (see Mixed and boundary value problems for hyperbolic equations and systems; Mixed and boundary value problems for parabolic equations and systems; Mixed-type differential equation). The term mixed problem is also applied to boundary value problems for elliptic equations when on various parts of the boundary conditions of different kinds are given (see Boundary value problem, elliptic equations).