Ah, serendipity! As it happens I'm working on a variant of HM type inference right now, so my first step was to look up the explanation on Wikipedia and have my eyes glaze over. (As the saying goes, 'Which part of [above equations] do you not understand?' Answer: all of it! And it's not even the first time I've looked at it, though I don't remember anything much from the previous time.)
Yes, I find typical Java style too verbose for optimal readability; but I find typical Perl style too terse for optimal readability. The sweet spot is somewhere in the middle.
So I rummaged around a bit more and found http://akgupta.ca/blog/2013/05/14/so-you-still-dont-understa... which explains the notation in much more readable English text. It's a pure win.
Yes, I find typical Java style too verbose for optimal readability; but I find typical Perl style too terse for optimal readability. The sweet spot is somewhere in the middle.