They are based on my book Calculus of Logic. The programs cover 38 %
of the text of the book.
A new notation has been adopted for some marks in the book, because
SWI-Prolog doesn't allow some marks in the book. The new notation has
been planned so that it is simple and fast to use. Some forms are so
difficult that they are almost impossible to form without the help of
ADP.

With the help of the programs it is easy to calculate in a moment
whether a long sentence is a tautology, a contingency, etc. ln the
same way you can simplify a long sentence in an instant. You can also
trnasform the form of a sentence very fast, e.g. a normal form into a
tabular form and vice versa. This was a dream of mine for tens of
years, because tedious manual calculation took hours and after that I
could be almost sure that the result was wrong due to some
miscalculation or clerical error.