What's purple and commutes? An abelian grape. What's purple and commutes and is worshipped by a limited number of people? A finitely-venerated abelian grape.

What's purple and commutes? An abelian grape. What's purple and commutes and is worshipped by a limited number of people? A finitely-venerated abelian grape. What's purple and had all of its children committed to mental hospitals? A simple grape (it has no proper, normal subgrapes).