A linear inverse problem for a three-dimensional mixed-type equation of the second kind, second order with semi-nonlocal boundary condition in an unbounded parallelepiped

We have investigated the correctness of a linear inverse problem for a three-dimensional second kind, second order mixed-type equation in an unbounded parallelepiped. The existence and uniqueness theorems for a generalized solution to a linear inverse problem for the equation with a semi-nonlocal boundary condition are proved in a certain class of integrable functions. The $\varepsilon$-regularization, a priori estimates, approximation sequences, and Fourier transform methods are applied.