His book, "Software Foundations" is here: http://www.cis.upenn.edu/~bcpierce/sf/ http://www.cis.upenn.edu/~bcpierce/sf/ And there's a discussion about the boo

His book, "Software Foundations" is here: http://www.cis.upenn.edu/~bcpierce/sf/ http://www.cis.upenn.edu/~bcpierce/sf/ And there's a discussion about the book from a year ago: https://news.ycombinator.com/item?id=7824793 https://news.ycombinator.com/item?id=7824793