pastek17: There is a suspicious branch in this exercise. If black tries D19 as first move then he is dead with F16 - F17 - E18 - H19 - F19. But instead of F19 the continuation proposed is E19 which brings black back to life if he plays F19 after E19. But after E19 - F19 the continuation proposed is E17 + "incorrect" message displayed while after E17 black is alive with F18.
There is a suspicious branch in this exercise. If black tries D19 as first move then he is dead with F16 - F17 - E18 - H19 - F19. But instead of F19 the continuation proposed is E19 which brings black back to life if he plays F19 after E19. But after E19 - F19 the continuation proposed is E17 + "incorrect" message displayed while after E17 black is alive with F18.