Binary correspondences are employed for formalization of the notion of problem, definition of the basic components of problems, their properties, and constructions (the condition of a problem, its data and unknowns, solvability and unique solvability of a problem, inverse problem, and composition of problems). As an illustration, we consider a system of differential equations which describe a process in chemical kinetics. Within the study of the inverse problem, a criterion is established for linear independence of functions in terms of finite sets of their values.

Keywords:differential equation, chemical kinetics, inverse problem, linear independence, binary correspondence, solvability, composition.