Studies of Euler diagrams/tavoku

This 3-ary Boolean function has 5 of 8 true spots. The representations here are inflated with the argument C, so that it looks like a 4-ary Boolean function.

In this inflated form it has these relationshipts:
 * It is inflated without spots 8 and 12.
 * Without spot 0 it becomes.
 * Without spots 0, 2, 6 it becomes

filtrates
Each of the 6 pairs is a 2-split (with all 4 quadrants). Only one of the 4 triples is a 3-split (with all 8 octants).