Re: The road to Artificial Intelligence

Now I have the feeling there are no difficult 9x9
Sudokus for the computer. At least not for computers
running SWI-Prolog and using CLP(FD) with the global
constraint all_distinct/1.
I was fishing among the 17-clue Sudokus, and the
hardest I could find so far was this one:
/* Gordon Royle #3668 */
problem(11,[[_,_,_,_,_,_,_,_,_],
             [_,_,_,_,_,_,_,1,2],
             [_,_,3,_,_,4,_,_,_],
             [_,_,_,_,_,_,_,_,3],
             [_,1,_,2,5,_,_,_,_],
             [6,_,_,_,_,_,7,_,_],
             [_,_,_,_,2,_,_,_,_],
             [_,_,7,_,_,_,4,_,_],
             [5,_,_,1,6,_,_,8,_]]).
But SWI-Prolog still does it in around 3 seconds.
SWI-Prolog does other 17-clue Sudokus in less than 100ms.
Are there any 17-clue Sudokus that take more time?
Mild Shock schrieb:

 Or a more striking example, Peter Norvig's impossible
Sudoku, which he claims took him 1439 seconds
to show that it is unsolvable:
 /* Peter Norvig */
problem(9, [[_,_,_,_,_,5,_,8,_],
             [_,_,_,6,_,1,_,4,3],
             [_,_,_,_,_,_,_,_,_],
             [_,1,_,5,_,_,_,_,_],
             [_,_,_,1,_,6,_,_,_],
             [3,_,_,_,_,_,_,_,5],
             [5,3,_,_,_,_,_,6,1],
             [_,_,_,_,_,_,_,_,4],
             [_,_,_,_,_,_,_,_,_]]).
 https://norvig.com/sudoku.html
 whereby SWI-Prolog with all_distinct/1 does
it in a blink, even without labeling:
 ?- problem(9, M), time(sudoku(M)).
% 316,054 inferences, 0.016 CPU in 0.020 seconds
  (80% CPU, 20227456 Lips)
false.
 Pretty cool!
 Mild Shock schrieb:

I didn't make all my homework yet.
For example just fiddling around with CLP(FD), I get:
>
?- maplist(in, Vs, [1\/3..4, 1..2\/4, 1..2\/4,
           1..3, 1..3, 1..6]), all_distinct(Vs).
false.
>
Does Scryer Prolog CLP(Z) have some explanator for that?
What is exactly the conflict that it fails?
>
Mild Shock schrieb:

>
Terence Tao, "Machine Assisted Proof"
https://www.youtube.com/watch?v=AayZuuDDKP0
>
Mostowski Collapse schrieb:

Don't buy your Pearls in Honk Kong. They are all fake.
>
So what do you prefer, this Haskell monster:
https://www.cs.nott.ac.uk/~pszgmh/countdown.pdf

>