On Wed, Jan 10, 2024 at 11:53 AM Michael Parson <mparson@bl.org> wrote:
My 16th printing of the 1978 K&R C book says:
Thanks for the idea.   I went to the bookshelf.  I had not thought to do that to see what the book would tell us -- duh.

FWIW:  I have two copies of the '78 edition (K&R1) that has a naked 3, and the second one has 10 9 8 7 6 5 4 3 - but still has a CMU Book Store sticker on its back saying it was $10.95 ;-)   [I used to keep one in my office and one at home].

So yes, it was set on the GSI C/A/T system, and I'm guessing the 3rd set was the first one that was actually sent to the printers. 
I wish I still had the copies of the proofs from Ted.