Studies of Euler diagrams/filtrates

To filtrate a Boolean function means to reduce its information about many sets to those of interest. Graphically it means removing circles from the Euler diagram and treating all merged cells as true, if any of the component cells are true.

This is a gap variant of Studies of Euler diagrams/examples. The 8 sets create 18 true cells and 3 gaps. Both B and C border all the three gapspots. Removing them merges the gapspots with their full neighbors.

The following filtrates leave a single gapspot.

Also a gap variant of. The 8 sets create 10 true cells and 8 gaps.

The 6 sets create 21 cells.