threatens to connect along the upper side (see variations). Then he threatens to make a living shape with , forcing White 4. Follows the awkward play at , needed to prevent a deadly bulky five. White must capture to prevent a lively bent four.
recaptures, recreating an earlier board position. This is called "eternal life". The game ends with no result under Japanese (and Korean) rules. On the other hand, this repeating play is prohibited under many rulesets which employ the superko rule. Black has to find a threat before he may play , just like in a ko fight. See the superko article for details.
What if White makes the Bulky five nonetheless. Isn't this ko? No, it isn't: Black has two outside liberties, enabling him to atari all White's stones. If White connects at the marked spot with instead, she creates a living 7 point eyespace inside Black's group.