Can an invention include several inventions?

Of course. For example, if you invent A, then A consists of A, B and C, in which A is your invention. But only as a patent application. According to the Patent Law and its detailed rules for implementation, an application for a patent for an invention or utility model should be limited to one invention or utility model. Two or more inventions or utility models belonging to a general inventive concept may be filed as one application. An application for a patent for a design shall be limited to a design used by a product. Two or more designs of products sold or used in the same category in sets may be filed as one application. Two or more inventions or utility models that can be filed as patent applications and belong to the general inventive concept shall be technically interrelated and contain one or more identical or corresponding specific technical features, in which specific technical features refer to the technical features that each invention or utility model as a whole contributes to the existing technology. The same category means that products belong to the same subcategory in the classification table; Complete set sales or use means that all products have the same design concept and are customarily sold and used at the same time.