A Peek into Einstein's Zurich Notebook (pitt.edu)

yeap, i got it too. Wonder why.

Same here … maybe just a hiccup.

Same problem here. Because I am outside US, maybe?

I am not a physicist, maybe one would elaborate on this, but it seems to be rather straightforward mathematics for a physicist to use (fancied-up calculus), and I don't know how a computer would help here at the level of development computers are today, my laymans impression is that the art here lied in choosing what to derive, not in the derivations themselves.