2012-01-19: In Section 6, “Constants”, the part of the regular expression

`LINE_PAT`

that recognizes one or more T, F, or X characters originally looked like this:r'[{1}+]' # Matches one or more T, F, or X

The “

`+`

” belongs outside the square brackets, like so:r'[{1}]+' # Matches one or more T, F, or X

2012-01-19: In Section 10, “

`Truths.__init__()`

”, neglected to establish the invariant for`self._caseCount`

. The fix is to add another prime at the end like this:#-- 5 self._caseCount = len0