A concept has almost always several others, which partially come under it, and each of these contains part of the sphere of the first, but also includes in its own sphere something more, which is not in the first.
Ia beti kontzeptu baten esferan beste askoz gehiago sailkatzen dira, zeinetarik bakoitzak lehenaren eremuaren atal bat bere baitan hartzen baitu, nahiz eta beste batzuk gehiago ere besarkatzen dituen: