What it's about
The title "Logic for Fun" pretty well sums up this site. It contains
logical puzzles, some but by no means all of the "what was the driver's
name" variety, together with a guide explaining how to express the puzzles
in a clear and simple way so that you can get the computer to solve them
Why would you do that? Well, apart from the enjoyment factor (and it is
quite enjoyable) you learn things. The challenge lies not in solving the
problems - after all, the computer does that for you - but in expressing
them precisely in the language needed for their logical solution. Whether
you think of this as a declarative programming language or just as first
order logic without all the special notation, it's a good thing to learn.
That said, you won't find here many technical definitions and
such, and you won't find any prescribed course, exam sheets of
anything of the sort. It really is all for fun. What you may
learn here is compatible with whatever else you may be studying,
but won't replace it.
You will notice that these pages are very plain. This is because you come
here to work and play with logical puzzles, not to be distracted by
backgrounds, irritated by animations, bored by badly-scanned images or
otherwise made to wish your browser could load the pages faster. Part of
the design philosophy has been to opt for simplicity and efficiency. I
hope you like that.
The full terms and conditions of use are set out on the form signed by the
person registering a group, or registering as an individual. All users
should note the following points:
Accounts are activated upon receipt of the fee. Users of an active
account may register at any time, and have unlimited access to the
site for one year, with a maximum of 1000 runs of the solver during
that time. There are no hidden fees or charges.
While we cannot absolutely guarantee that our site will be immune to
virus attacks etc, we do pledge not to send you advertising material
or other unsolicited mail beyond what is involved in operating the
account, and to take all reasonable steps to avoid being party to your
address reaching any mailing lists.
Everything on this site is covered by copyright. Storing and printing
of the pages for your own private use or for educational purposes
internal to a course which is registered as a "group" is permitted.
Any other copying or distribution of the material is a breach of
copyright unless express permission has been obtained in advance from
the Australian National University. For more information, click
This site is part of a university. While using it, you are expected to
behave appropriately. Attempting to crash the web server, annoying
other users and suchlike are not funny and we reserve the right to
cancel the registration of any user found to be acting in such a
Users must not gain or attempt to gain unauthorized access to
information stored on any of the Australian National University's
computers. Breach of this condition is a criminal offence.
There are two fee schedules: one for individual accounts and
one for groups.
Formerly, there was another option for groups to pay a flat fee of AUD
10.00 per head in arrears. This option is no longer available.
Fees are in Australian dollars. Goods and Services Tax (GST) of 10% is
included in the price.
For groups, we are usually prepared to quote a price in your local
currency rather than in Australian dollars. Please ask for details at the
same time as registering your group.
Individual accounts are valid for one year from the date of
activation. Group accounts remain valid indefinitely until you tell us
otherwise. A list of group members is maintained by the group organiser,
and anyone whose name is on the list may register as a user at any time.
Under Schedule B, an amount is paid in advance for an estimated number of
users, and then names up to that number may be added at any subsequent
time. The account may be "topped up" with further payments at any time.
Each user is entitled to run the solver up to 1000 times in the 12 months
following registration. This is more than enough for the average student
to complete the puzzles (and for users in a group this prices solutions
(in US currency) at under a dime a dozen).