The handwriting is not great (though let he who can calligraph with a mouse pointer cast the first stone), but, however good or bad it is, the `\pi` clearly is not the main symbol, and the `x^2` and `dx` (which, as has been mentioned (https://news.ycombinator.com/item?id=12388859), inexplicably renders as `d_x`) are clearly at the same height.