tarek wrote:

how many did you show a walkthrough solution for ? the answer is 0.

Tarek, you have forgotten the occasion on Nov 23 when I used the technique (taught by my friend) to map the digits in one box of the original puzzle onto the digits in another box of the equivalent puzzle to prove that the last row of boxes did not interchange with the first row of boxes.

In the normal practice of the puzzle world, there is no need for a puzzle maker to reveal the solution or the steps leading to the solution. Just visit any puzzle website or read any puzzle book, how many of them had revealed the answers? The request only comes when somebody suspects that even the puzzle maker does not know the answer himself. Of course, this is ridiculous. As a maker of the puzzle, he should already know every clue and every line of reasoning in the puzzle.

The best reward for a puzzle maker is to see somebody provide a solution and show the steps leading to the solution, not himself. Otherwise why the need to publish his puzzle? He might as well sit at home every night solving his own puzzle himself.

Tarek's request is similar to one story I know. A chef had baked a new type of cake and invited some friends to his house to have a taste of it, hoping to get some comments from his friends on the new cake. After eating the cake, everybody kept silent except one friend commented that the cake tasted sweet enough.

To the disappointment of the chef, however, another friend told him to eat his own cake so as to prove to everybody the existence of sugar in the cake. Of course, it was ridiculous for the chef to eat his own cake so as to find out whether there was sugar in it. As the maker of the cake, he should already know what ingredients he had used to bake the cake, how many grams of sugar he had added to it, etc.

What would delight him was to hear the comments of others, not to get the request to eat his own cake so as to prove the existence of sugar in the cake. In the end, the chef suspected that he had forgotten to add sugar during the process of baking, so he finally ate his own cake.

I have to thank Pat for her help in posting the grids with all the available clues. You won't be disappointed as the steps leading to the solution would be revealed either by me (taught by my friend) or somebody else within a few days.