There’s a picture at the bottom. I think the text there is a bit more clear (maybe?): you have a cubic surface and want to see if there’s any “straight line” th

There’s a picture at the bottom. I think the text there is a bit more clear (maybe?): you have a cubic surface and want to see if there’s any “straight line” that lives/lies on the surface. It turns out there’s 27 lol.