Pyrrhon wrote:

...(Henry Kwok has devloped more interesting sudoku variants)...Other equivalence classes could be better, for example the class Kwok used in his other invention, called twin corresponding sudoku. Also the restriction to changes of chutes was a better idea. But all this was made clear by the discussion here. And so the discussion was fruitful even because the puzzles were not so good.

Pyrrhon, my friend is glad at least to hear a few nice words from you. Just using an analogy about the farce here, a person had posted a puzzle which consisted of a group of 3 coins on each side with the instruction that the solver had to interchange the position of each group of coins by moving a coin towards the other group and letting another coin from the other group jump over it.

Some jokers came along and raised a farce by bringing in some university mathematics and posted a puzzle with 1000 coins on each side and made it into a problem of interchanging the position of 1000 coins.

My friend has never declared or boasted that he has discovered any super mathematical theorem, otherwise he would have announced it at a top university or at a mathematical society gathering. He is adapting a well-known mathematical concept to make a very simple puzzle that is solvable even by students. The puzzle just consists of at most two simple transformations with plenty of clues available unlike those that consist of over 70,000 permutations that need "machine solutions". It is analogous to the simple puzzle with 3 coins on each side, not 1000 coins.

udosuk wrote:

From what I see, Shintaro's "step-by-step explanation of the solution" is not logically sound, and thus not considered "convincing" by many entities here who have participated in the discussion...Now I'm really interested, how many aliases (friends ) does Mr. Henry Kwok have...

Now the ball is in the court of udosuk and other armchair critics to "improve" on the method of solving or offer an alternative method, otherwise they are simply NATO's. In my friend's country, there is a popular term known as "NATO" which means "No action, talk only". It is a term reserved for armchair critics who just criticise but unable to offer any alternative solution.

So far the method has just been dismissed as "guessing", "not logically sound" and "unconvincing" with nobody providing any good explanation, refutation or alternative. None has yet to refute the method by contradiction.

His method is analogous to that used by police making whatever available at the scene of a crime. Imagine a detective had entered a room (analogous to the sudoku grid) where he found a number of objects (analogous to the digits) at the scene of a crime.

He found lipstick, a high-heel shoe and a lady's handkerchief (analogous to the 3 six's in the middle of the puzzle). The first idea that comes to anybody's mind is naturally that the criminal was a female. Anybody would come to this conclusion and uses the object as clues for his detection until he discovers a contradiction halfway. The method is natural and logical as there are no other ways for the detective. So don't just dismiss it as illogical or unconvincing, otherwise the detective simply made no headway.

Here I have to repeat and emphasize it again. My friend has never declared that he has invented or discovered any super theorem. This variant is made so simple with one or two transformations that even some students can solve it. So what is the farce of bringing in all the mathematical stuff fit for university academics?

If anybody considers his solution as rickety as an old cart, then he should try to invent the car or at least a better cart, not just criticise. If he can't make a car, he has either to walk or just ride on the old rickety cart.

udosuk, my friend is waiting for you at

http://www.sudoku.org.uk/discus/messages/1289/1289.html?1165183777.There you can ask him any question to your heart's content. It looks like he feels very lonely there, without any business or anyone to keep him company!