To: cube-lovers@life.ai.mit.edu
Subject: Re: 10x10 Tangle

Sorry about not reporting this earlier, but my search for solutions for
Rubiks Tangle 10x10 confirms the finding of Don Woods: no solutions!

Dik Winter writes:
>As I wrote before, I have embedded in my memory that there is an easy
>argument that the 10x10 is *not* solvable. I do not know whether I
>found it myself (and ever did mail it to other people) or whether I
>found it somewhere on the net; it is a long time ago. When I find the
>time I will do a check. (I know very sure that I have had a program
>running at that time but that I abandoned the search because it would
>be fruitless.)

I am beginning to get real curious about that 'easy argument'.
Does this argument depend on the particular choice for the four
duplicated pieces or not?
If it does, there could exist a choice that does allow a solution, and
we could re-define the puzzle as follows:
find which four pieces to duplicate in order to find solutions for
the 10x10.
If the number of solutions varies depending on the choice, you could
even add a restriction:
find which four pieces to duplicate in order to find a set which has
the minimum number of solutions for the 10x10.

But if the easy argument does NOT depend on the choice, i.e.: any
choice would lead to no solutions, then the above puzzles would be
senseless as well.

So if anyone at all knows this argument, please tell us and solve the
mystery.

Jan