Estimation of the conditional stability of an ill-posed initial-boundary problem for a high-order mixed type equation.

In this paper, an ill-posed problem for a higher-order mixed-type differential equation is investigated on conditional correctness. A priori estimate for the solution of the problem is obtained and theorems on uniqueness and conditional stability in the corresponding set of well-posedness are proved. It is shown that the results obtained are applicable to the initial-boundary value problem for a system of mixed type equations. [ABSTRACT FROM AUTHOR]