Good point. The rendering of "sufficient" probably uses the triple-ligature for "ffi", where all 3 characters are merged.

The author, Peter Cheeseman, is a reputable figure and a solid practitioner. I'm sure he's just as annoyed that, on the second page, his own name is misspelled as "Cheesemart" ;-).

People may recognize him as a co-creator of the AutoClass software for Bayesian clustering, which was very popular in the late 1990s - the explanatory paper has 1700 citations.

We can fix it. I have started a git repo for this https://github.com/michaelchristophernewyork/probability

please help clean up if you have time.

Author's name is also misspelled in the header on one of the early pages. It's obviously been scanned and OCRed.

OCR has come a long way, but still has lots to improve.