Flying Saucer Shape
The critical elements are
- the black group's weak spots are occupied by White ( stones),
- the black group is blocked on the second line at both ends ( stones), and
- these white blocking stones are connected to the rest of the white group ( stones).
It is not critical whether the circled liberties are occupied or not.
For an example of a flying saucer position where the third critical element is missing, see Gokyo Shumyo, Section 1, Problem 23.
For a general treatment, see Two Space Notchers Not Fully Connected.
White cuts at the other side than the one Black protects, then gives atari. She finishes off with , keeping Black at one eye. The position is symmetric, so if at 3 then at 5.