Haha, I felt smart for a second because I got the "non-trivial" example immediately, but then realized my browser history for the past month consists of researc

Haha, I felt smart for a second because I got the "non-trivial" example immediately, but then realized my browser history for the past month consists of research on convex vs non-convex optimization problems, so I feel I had a bit of an unfair advantage there.