New book "The Hidden Logic of Sudoku"

berthier · Posted: Thu Jun 14, 2007 2:40 pm Post subject:

[quote="gsf"]so the straification of levels 03-10 is based on sizes of (in my solver) matched XYK structures
[quote]
You mentionned several times XYK constraints (and BRNet), which I don't know. I couldn't find this in Ruud's list in the Solving Sudoku Forum.
Could you give me a reference?
Thanks.

Red Ed · Posted: Thu Jun 14, 2007 5:58 pm Post subject:

BR nets, which I defined purely for theoretical interest, are defined in this post: (here).

gsf's "ternary monoids" theory was the inspiration for BR nets. I'll leave gsf to explain that.

gsf · Posted: Thu Jun 14, 2007 7:10 pm Post subject:

gsf · Posted: Thu Jun 14, 2007 7:19 pm Post subject:

[delete]

berthier

After several people asked for more information on the content, I put some excerpt on my Web pages (http://www.carva.org/denis.berthier)

berthier · Posted: Thu Jun 21, 2007 2:52 pm Post subject: Extended Sudoku board

As a complement to the book, and in order to make my resolution method easier to apply, I have devised an extended Sudoku Board, whith the two additional rn- and cn- spaces.
You can download it for free either on my Web pages or on the publisher's site:
http://stores.lulu.com/berthier

vittyken

[quote="berthier"]This is to announce to this forum that I have just published a new book "The Hidden Logic of Sudoku", which may be of interest to some of you.]

I just got the book through Amazon yesterday and I read the prologue and the introduction.
I will admit I haven't read, in my estimation, a college level book in some time.
But from what I understand I will be using it to help me solve the most difficult Sudoku around.
What I am interested in knowing is will the book help explain a lot better the advanced situations of the xy-wing and higher than does some other Websites try to do? You wrote that the rules will be first in plain English and then it will go into the technical jargon: logic formulas with expressions.
I've read most of Hofstadter's GEB and can relate to the "strange loops" one can get into when doing a Sudoku puzzle.
Thank you for writing this book.
On a curious note, how long did it take you to write this? You first saw a Sudoku puzzle in Dec 2005 and published this book in 2007. Very impressive.
Thanks again.
Ken

berthier

vittyken · Posted: Wed Oct 24, 2007 5:31 am Post subject: programming a spreadsheet

On page 36, you said it "is an easy exercise to program a spreadsheet for computing the three new grids and their canditates...".
Is there an easy program?

vittyken

Ruud · Site Admin

I have built RN and CN views into SudoCue. You can find more details in my release notes.

Ruud

vittyken · Posted: Wed Nov 21, 2007 5:40 am Post subject: SudoCue

In a word, WOW!
It always makes me happy when a little programming knowledge solves a problem or follows a process.
I am flabergasted when a lot of programming knowledge does something like what you did.
Thanks a lot.
The next thing I am looking for is how to create a sudoku puzzle manually.