Talk:Nonlinear finite elements/Solution of heat equation

From "Computing M, K, f" onwards I find this page incomprehensive. I don't know what we try to do, how and where it's going to take us.

Some "stiffness matrix" shows up that hasn't been mentioned before (I think) and it's not clear what it is about.

It seems like we use quadrangular elements, but why and how has not been introduced. Aren't triangles more common? Isn't the subject of grid creation somewhat important? Maybe we don't have to explain it all, but at least point out that something 'fancy' is happening there. And it needs to be fleshed out.