-;;; This takes a digit guess, multiplies it by *truncate-y* for a result one
-;;; greater in length than len-y, and subtracts this result from *truncate-x*.
-;;; Low-x-digit is the first digit of x to start the subtraction, and we know x
-;;; is long enough to subtract a len-y plus one length bignum from it. Next we
-;;; check the result of the subtraction, and if the high digit in x became
-;;; negative, then our guess was one too big. In this case, return one less
-;;; than guess passed in, and add one value of y back into x to account for
-;;; subtracting one too many. Knuth shows that the guess is wrong on the order
-;;; of 3/b, where b is the base (2 to the digit-size power) -- pretty rarely.
+;;; This takes a digit guess, multiplies it by *TRUNCATE-Y* for a
+;;; result one greater in length than LEN-Y, and subtracts this result
+;;; from *TRUNCATE-X*. LOW-X-DIGIT is the first digit of X to start
+;;; the subtraction, and we know X is long enough to subtract a LEN-Y
+;;; plus one length bignum from it. Next we check the result of the
+;;; subtraction, and if the high digit in X became negative, then our
+;;; guess was one too big. In this case, return one less than GUESS
+;;; passed in, and add one value of Y back into X to account for
+;;; subtracting one too many. Knuth shows that the guess is wrong on
+;;; the order of 3/b, where b is the base (2 to the digit-size power)
+;;; -- pretty rarely.