The document says:

char-set-unfold  f p g seed [base-cs] -> char-set
char-set-unfold! f p g seed base-cs -> char-set

The sample implementation has

(define (char-set-unfold p f g seed . maybe-base)
(define (char-set-unfold! p f g seed base-cset)

The file srfi-14-tests.scm has

	    (char-set-unfold null? car cdr '(#\a #\e #\i #\o #\u #\u #\u)
	    (char-set-unfold! null? car cdr '(#\a #\e #\i #\o #\u)
		 (char-set-unfold! null? car cdr '(#\a #\e #\i #\o #\u)

which matches the implementation but not the document.

What to do?

Brad

PS:  Also, change "complimented" to "complemented" in the document.