Confusion about seki (solved)

[Civilian]

Hello, very new player here with a rules question
I just watched this 9x9 match and the computer says black is barely winning and that the white group in the bottom left ist dead.
I don’t quite understand why that is - isn’t the situation bottom left a seki?

https://online-go.com/game/38454821

[stone_defender]

it is called bent 4 Bent four in the corner is dead at Sensei's Library

[Civilian]

Oh well, thank you very much! Couldn’t find the correct move for black, this will certainly be helpful in the future

[Groin]

Added a review for your last chance to live (and win)