Date: Fri, 24 Apr 92 14:56:22 -0700 (PDT)
From: Don Woods <Don.Woods@eng.sun.com >
~~~ ~~~ Subject: Description of Rubik's Tangle

From: Allan C. Wechsler <ACW@riverside.scrc.symbolics.com>
I hope I'm not wasting too many people's time, but... can you describe
the Rubik's Tangle puzzle for those of us who haven't seen it? Your
can't be solved without a computer. Perhaps you just didn't have the
right insight.

I would love to hear an insight that makes this puzzle tractible in real
time (hours rather than days) by hand. Here's a brief description of
Tangle #1; as I said in my earlier posting, I don't know how the other 3
differ, though I'm pretty sure they each have the same number of tiles.

Tangle #1 consists of 25 square tiles, each of which has four colored
ropes crossing it in the following pattern. (Note: This may be mirror
imaged, since I'm working from memory.)

```---------------------
|     @       #     |
|     @       #     |
|\$\$    @      # %%%%|
|  \$    @    %#%    |
|   \$    @ %% #     |
|    \$    %@  #     |
|    \$  %%  @@#     |
|    %%%      #@@   |
|%%%% \$       #  @@@|
|     \$       #     |
|     \$       #     |
---------------------
```

The connection marked with \$ actually wanders around the tile a bit more,
but the connectivity is as shown. The object is to place the tiles in a
5x5 array such that wherever two tiles touch the colors of the ropes match.
In Tangle #1 each permutation of colors occurs once, with one permutation
occurring twice.

The box says that if you get all four Tangles, you can put them together
to make a 10x10 array under the same color-matching constraints.

```-- Don.
```