[ULPIANUS libro quadragesimo sexto ad Sabinum. ] §19.1.10.prNon est nouum, ut duae obligationes in eiusdem persona de eadem re concurrant: cum enim is qui uenditorem obligatum habebat ei qui eundem uenditorem obligatum habebat heres exstiterit, constat duas esse actiones in eiusdem persona concurrentes, propriam et hereditariam, et debere heredem institutum, si uelit separatim duarum actionum commodo uti, ante aditam hereditatem proprium uenditorem conuenire, deinde adita hereditate hereditarium: quod si prius adierit hereditatem, unam quidem actionem mouere potest, sed ita, ut per eam utriusque contractus sentiat commodum.
[ULPIANUS, on Sabinus, Book 46] It is nothing new for two obligations to concur in the same person concerning the same thing: for when someone who held a seller obligated becomes the heir to another who held the same seller obligated, it is established that there are two concurrent actions in the same person, his own and the inherited one, and that the appointed heir, if he wishes to enjoy the benefit of the two actions separately, must sue his own seller before accepting the inheritance, and then, after accepting the inheritance, sue the inherited one; but if he accepts the inheritance first, he can indeed bring only one action, but in such a way that through it he realizes the benefit of both contracts.
ex contrario quoque si uenditor uenditori heres exstiterit, palam est duas euictiones eum praestare debere.
Conversely, also, if a seller becomes the heir to a seller, it is clear that he must guarantee two warranties against eviction.