From dik@cwi.nl Sun Jan 2 21:52:23 1994 Return-Path: Received: from charon.cwi.nl by life.ai.mit.edu (4.1/AI-4.10) for /com/archive/cube-lovers id AA16116; Sun, 2 Jan 94 21:52:23 EST Received: from boring.cwi.nl by charon.cwi.nl with SMTP id AA27901 (5.65b/3.12/CWI-Amsterdam); Mon, 3 Jan 1994 03:52:21 +0100 Received: by boring.cwi.nl id AA07139 (4.1/2.10/CWI-Amsterdam); Mon, 3 Jan 94 03:52:20 +0100 Date: Mon, 3 Jan 94 03:52:20 +0100 From: Dik.Winter@cwi.nl Message-Id: <9401030252.AA07139.dik@boring.cwi.nl> To: Don.Woods@eng.sun.com, cube-lovers@ai.mit.edu Subject: Re: 10x10 Tangle > Has anyone out there ever heard definitely that someone has found a > solution to the 10x10? 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.) > Is it possible that the makers of Tangle (Matchbox, > using Rubik's name under license) merely claimed that such a solution > exists, without actually verifying it? Yes, very probable. You should never trust the number of solutions the manufacturers give. Sometimes it is much more, in this case it is less. An actual example is a puzzle that consists of of nine rings (eh, this is from memory, I do not have access to the puzzle at this time). Five rings contain digits; three rings contain operators; one ring contains equal signs. All in four positions around the rings. The idea is to create correct sums (like 5 + 1 - 4 + 1 = 3) on all four positions of the rings. The claim was that there was only a single solution. Actually there are many. If there is interest I can hunt down the rings and describe them in more detail. (An interesting detail is that my father was the first to find the puzzle; he had correct solutions like: 1 + 3 : 2 + 1 = 3. He was a physicist. The accomanying leaflet did not give details about operator priorities. Hence it actually makes two puzzles; one with regards to priorities, the other just going left to right.) > (Seems pretty sleazy if so, > but then, having Tangles 2-4 be merely color permutations of #1 is > pretty weak in the first place.) Indeed, the mass manufacturers are sleazy. Cheers. I will mail when I find back the argument disallowing 10x10. -- dik t. winter, cwi, kruislaan 413, 1098 sj amsterdam, nederland, +31205924098 home: bovenover 215, 1025 jn amsterdam, nederland; e-mail: dik@cwi.nl