I ordered a 1962 edition of book 1 and a 1975 edition and will compare with the Brown 2000 edition (the final entry in the series). If I can, I'll report back here.
In reading the blog post, I compared what she wrote with my Brown 2000 edition. The blogger said that a 1988 edition had only 6 oral and 20 written exercises in the topic she was comparing between the three books, vs. 30 for the oldest edition. My 2000 edition had 30 oral and 60 written exercises, but did suffer from the fill-in-the-blanks proof problem she identified in the 1988 edition. The detail about closure, etc. was missing.
Interesting. Thanks for the link.
