An arrow has a head and a tail. There is a mistake in the diagram above, can you locate it?
We can get from one diagram to the next by mutation at a given vertex, fro example, mutation of the grey vertex of A gives B. Can you guess how we get to C, D and E.
This is a tree diagram for the quivers above. At the base is the quiver A while the position of D and D' is shown.
Each of the dark blue points in the diagram correspond to a position for some quiver. Can you locate the positions of B, C and E?