Resolving a problem of differential diagnostics

A problem of differential diagnostics of functional state of controlled objects having the module structure and possessing a finite choice of possible disrepairs can be reduced into two independent sequentially solved problems: the checking problem, i. e. the recognition criterion of existence of disrepair in a system, and the problem of diagnostics, i. e. the search of disrepair. The exit of the object trajectory to some checked manifold may be the criterion of existence of disrepair in the system. The disrepair can occur at any unknown moment of object motion and in any point inside that manifold. The problem of diagnostics can be resolved by tracing of the object trajectory after its exit to the checking manifold. The notion of the space of diagnostics is presented. Such space has weaker properties than the general topological space.