First of all, many thanks for the interest!

I really feel I am not working in vain. Currently I am working on quite a big upgrade to the puzzles, adding some actors there. The new version will be like a cross-over of 2 types of Smullyan's puzzles - the doors + knights/knaves.

quote:

**Nuntar wrote**:

Just a quick point about your user's manual:

* All green doors are safe. <-> At least one of the green doors is a trap.
* Either all green doors are safe, or they all are traps.
<-> Some green doors are safe, others of them are traps.
* Two of green doors are safe. <-> Two of green doors are traps.

The last one doesn't follow. The logical negative of "

Two of the green doors are safe"

is "

Either more than two or fewer than two of the green doors are safe"

.

Yes, right. The last rule does not follow the common logic's negation principle. To make the negation consistent, I am going to remove this one from the puzzles in the next version.

quote:

**Nuntar wrote**:

How many rooms are there, anyway? I've got through the first 50 now, and the sign on my door, which happens to be a truthful one, says that I'm getting a little bored by now

I want to say, that the puzzles are generated by a computer, they are not written anywhere, byt generated randomly on-the-fly. The number of puzzles is virtually endless.

Computer also ensures that every generated puzzle is consistent. Till now no unsolvable or inconsistent puzzles have been encountered, so I am quite sure the engine works properly (Except the moments when I have updated the software on site, and the software was buggy

)

Just for info - if you have found a puzzle which looks like a bug in the puzzle engine, please post a link to it here, do not cite the door signs, because the link contains the seed by which I can check how the puzzle is generated.

Let's think about this one:

quote:

**Door 1 (yellow). Sign reads:**

The green door is safe to enter.

The door number 2 is lying.

**Door 2 (green). Sign reads:**

Either all the doors are traps, or they all are safe to enter.

One of the doors is lying.

**Door 3 (yellow). Sign reads:**

Some of the yellow doors are traps, some are safe to enter.

Let's start with checking the expressions on door 2. If it tells truth, then all doors are safe to enter (all cannot be traps), then door3 lies, and door 2 should tell truth, because the first expression on door 1 is true. But the second expression on door 1 creates a problem - it is contrary to our speculation on the state of door 2 (that it tells truth.)

By this, we have proven that door 2 lies. What can we derive out of this fact?

(1) Some doors are traps, some are safe.

(2) Only one of doors tells truth.

Then which one tells truth? Look at door 1. It supposes that door 2 is lying, which is truth. The first expression there should be also true, means we can enter the door 2.

The door 3 is lying (2). Both of yellow doors are either traps, or safe. If they would be safe, it goes contrary to (1). So they are traps.

This one:

quote:

**Door 1 (yellow). Sign reads:**

Some of the doors tell truth, some are lying.

**Door 2 (brown). Sign reads:**

At least one of the doors is safe to enter.

**Door 3 (green). Sign reads:**

Two of the doors, which lie are safe to enter.

At least one of the odd doors is safe to enter.

**Door 4 (yellow). Sign reads:**

Either all the doors tell truth, or they all are lying.

Door 2 tells truth, that is right.

If door 4 tells truth - then door 1 lies, which renders the expression on door 4 impossible. Door 4 lies, door 1 tells truth.

Now we are not sure about the door 3. If it tells truth, then there must be at least 2 lying doors. But we have only door 4 lying! Means, door 3 also lies.

Inverting the doors 3 expressions:

(1) Two of the doors which lie are traps.

(2) All the odd doors are traps.

We have solved the task with the following answer:

Door 1 truth, trap (2);

Door 2 truth, safe (because there must be a safe door!)

Doors 3 lies, trap (1);

Door 4 lies, trap (1);

Thanks again for your interest, have fun!

Kind regards,

Peter.