Romanov's theorem

Romanov's theorem refers to a result in the field of mathematics, specifically in the area of functional analysis or approximation theory. However, there may be various references and contexts in which "Romanov's theorem" is used, as the names of theorems can often relate to the work of specific mathematicians. One possible reference is the theorem related to the approximation of certain types of functions, often concerning the properties of interpolation or approximation in normed spaces.