Complex sentence: Any particular vector file format supports only some kinds of one vector file format is converted to a file format that supports all the primitive objects used in that particular image, then the conversion can be lossless.
Split into simpler sentences: Any particular vector file format supports only some kinds of primitive objects. If an image stored in one vector file format is converted to a file format that supports all the primitive objects used in that particular image, then the conversion can be lossless.