WARNING: POSSIBLE SPOILERS

The premise of this game is basically the opposite of the "Logic Puzzle
Sampler". Yes, the paper changes color according to the truth of the
statement on it. But the real point is to force the papers to be a
certain color, and thus cause the real world to change. (Actually, they
only *look* a different color.)

The game uses a modified version of Andrew's sample code. I've simplifed
it so that you can refer only to the colors of objects. (The other
predicates are unneeded.) I also changed the genie into a printer.

The key to solving this game is the transparent sheet protector, which
can be printed on. Placing another paper inside causes it to look a
certain color, and force the world to change to make the paper
accurate. In this game, we want the light to be green. So, we could write
on the shiny paper, "The traffic light is green." and write on the sheet
protector, "The printer is grey." (which is true). Then put the shiny
paper into the sheet protector.

If you put a blank piece of paper into the sheet protector, it won't
change. It makes no claim, so it can't be forced to change. Of course, it
might *look* a certain color through the transparency, but it still
retains its old color.

If both the sheet protector and its paper refer to the same object, this
is considered a paradox. It is also possible to make blank paper really
not white. If you "force" a change in the color of something, all papers
that refer to it change accordingly.

Coding all this took many hours of writing, testing, debugging, and
hacking of Zarf's code. If you like, you can view the mess of global
variables, jump statements, bad interface design, and a few
elegant hacks in the source code (public domain).

Some fun (or not) things to do:

You can change the color of the printer itself. So instead of being
shaded an ugly grey, it could be shaded an ugly purple. (Ugh!)

If you change the light to anything except red, you can still cross. If
you cross when the light isn't green, yellow, or red, the news report
will quote an engineer as stating that he's baffled at how the light
could display, say, blue. (There are three lights on the traffic
light. Which one shines when the light is blue?)

I was going to have another logic puzzle in here that was required in
order to be able to use the printer. But I'd already used that one
before, so to put it in would violate the rules ("must be an original
work, never before released"). I regret not being able to put it in.

Finally, I must say that I'll be looking forward to seeing the other
entries.

Eric Schmidt (eschmidt@safeaccess.com)