Yes, right, the idea is to determines ALL implication chains.

Easiest thing to do is clip that into

http://www.stolaf.edu/people/hansonr/sudokuyourself. Just click on "Number block input", paste the table in there,

and press "puzzle".

It wouldn't be able to show all the implications, because it generally

doesn't continue through if it finds an inconsistency. For example, when I

do that and then press "Step" I get:

Strong Chains: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

Cross checking

60 cells left to solve; 21 clues; 483 tidbits of information

[snapshot]

Checking block ranges

Checking for subset elimination

Checking for grids

Checking strong chains

17 strong chains

Checking for weak links

44 weak links

139 weak corners

r9c2 ISN'T 9: weak corner eliminated by both 2(b) and 2(B)--4(D)

Chain 2: r1c6#4(b) r1c8#4(B) r2c5#4(B) r2c7#4(b) r5c2#4(B) r9c2#4(b) r4c3#4(b) r8c3#4(B) r4c7#4(B) r5c8#4(b) r8c5#4(b) r9c6#4(B)

Chain 4: r2c1#9(d) r7c1#9(D) r3c2#9(D)

The fact that it went on to the weak link check tells me that the

chains are all OK -- no end-nd problems. But it isn't going to keep

going and check all. I guess you could adjust the code to do that.....

You can check the "chain table" yourself. It looks like this in this case:

- Code: Select all
`16 strong chains are labeled A-P, with alternating parity shown using lowercase.`

|---c1---|---c2---|---c3--||---c4---|---c5--|---c6--||---c7--|---c8---|---c9---

----------------------------------------------------------------------------------

r1 | 56 | 56 | 2 || 358 | 9 | 348 || 1 | 34568 | 7

| aA | bB | || | | c || | C |

---+--------+--------+-------||--------+-------+-------||-------+--------+--------

r2 | 1579 | 3 | 8 || 6 | 2457 | 124 || 245 | 459 | 259

| e fd | | || | j F | E || l | |

---+--------+--------+-------||--------+-------+-------||-------+--------+--------

r3 | 4 | 15679 | 157 || 123578 | 2578 | 1238 || 2568 | 35689 | 235689

| | D | || | | || | | n

=============================||========================||=========================

r4 | 12367 | 124678 | 1347 || 23789 | 2678 | 5 || 2468 | 146789 | 12689

| | | g || h k | | || L | |

---+--------+--------+-------||--------+-------+-------||-------+--------+--------

r5 | 2567 | 245678 | 9 || 278 | 1 | 268 || 3 | 45678 | 2568

| | i | || | | || | I |

---+--------+--------+-------||--------+-------+-------||-------+--------+--------

r6 | 123567 | 125678 | 1357 || 4 | 2678 | 23689 || 2568 | 156789 | 125689

| | | || | | H K || | |

=============================||========================||=========================

r7 | 123579 | 12579 | 1357 || 12589 | 2568 | 12689 || 568 | 13568 | 4

| D | | || | | || | n |

---+--------+--------+-------||--------+-------+-------||-------+--------+--------

r8 | 135 | 145 | 1345 || 158 | 4568 | 7 || 9 | 2 | 13568

| | | G || | J m | || | | N M

---+--------+--------+-------||--------+-------+-------||-------+--------+--------

r9 | 8 | 12459 | 6 || 1259 | 3 | 1249 || 7 | 15 | 15

| | J | || | | j || | oO | pP

----------------------------------------------------------------------------------

Chain Implication Table

1(a)--> 2(B) row 1

1(A)--> 2(b) row 1

2(b)--> 1(A) row 1

2(B)--> 1(a) row 1

3(c)--> 10(J) block 2

3(C)--> 9(i) col 8 12(L) block 3

4(d)--> 5(E) r2c1 6(F) r2c1

5(e)--> 4(D) r2c1 6(F) r2c1

6(f)--> 4(D) r2c1 5(E) r2c1

6(F)--> 10(J) r2c5

7(g)--> 9(I) block 4 12(l) row 4

7(G)--> 10(j) row 8

8(h)--> 11(K) r4c4

8(H)--> 11(k) r6c6

9(i)--> 7(G) block 4 10(j) col 2

9(I)--> 3(c) col 8 12(l) block 6

10(j)--> 3(C) block 2 6(f) r2c5 12(L) row 2

10(J)--> 7(g) row 8 9(I) col 2 13(M) r8c5

11(k)--> 8(H) r4c4

11(K)--> 8(h) r6c6

12(l)--> 3(c) block 3 10(J) row 2

12(L)--> 7(G) row 4 9(i) block 6

13(m)--> 10(j) r8c5

13(M)--> 14(n) r8c9

14(N)--> 13(m) r8c9

15(o)--> 16(P) row 9

15(O)--> 16(p) row 9

16(p)--> 15(O) row 9

16(P)--> 15(o) row 9

OK, so there are a lot of implications here.

HINT: Use the "load puzzle" link from this pop-up window each time you

want to reset the configuration to this one. Or you can also click the

"snapshot" link that shows up with the information.

If you start disabling things, you might be able to get some different

answers:

** checking +almost-locked sets (Y):

Cross checking

60 cells left to solve; 21 clues; 483 tidbits of information

[snapshot]

Checking block ranges

Checking for subset elimination

59 almost-locked sets (Y)

r8c3 ISN'T 1: weakly linked to two almost-locked sets already weakly linked by 7: r3c3 and r7c3 r8c1 r8c2

** checking X-cycles only:

Strong Chains: 1 2 3 4 5 6 7 8 9 10 11 12 13 14

Cross checking

60 cells left to solve; 21 clues; 483 tidbits of information

[snapshot]

Checking block ranges

Checking for subset elimination

Checking for grids

Checking strong chains

14 strong chains

Checking for weak links

4 weak links

16 weak corners

r5c1 ISN'T 7: weak corner eliminated by both 6(f) and 6(F)--7(G)

Chain 6: r2c1#7(f) r2c5#7(F)

Chain 7: r3c4#7(g) r5c4#7(G)

(note, these are differerent chains than above)

**Edges only:

(This is just a demo mode that only considers the shortest chains and

misses some due to that.)

Strong Chains: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

Cross checking

60 cells left to solve; 21 clues; 483 tidbits of information

[snapshot]

Checking block ranges

Checking for subset elimination

Checking for grids

Checking strong chains

25 strong chains

Checking for weak links

62 weak links

135 weak corners

r1c8 ISN'T 3: weak corner eliminated by both 3(C) and 3(c)--23(w)

Chain 1: r1c1#5(a) r1c1#6(A)

Chain 2: r1c2#5(b) r1c2#6(B)

Chain 3: r1c6#4(c) r1c8#4(C)

Chain 7: r2c5#4(g) r2c7#4(G)

Chain 8: r5c2#4(h) r9c2#4(H)

Chain 9: r2c1#7(i) r2c5#7(I)

Chain 10: r2c8#5(j) r2c8#9(J)

Chain 12: r4c3#4(l) r8c3#4(L)

Chain 13: r4c4#3(m) r4c4#9(M)

Chain 15: r4c7#4(o) r5c8#4(O)

Chain 20: r8c5#4(t) r9c6#4(T)

Chain 21: r8c5#6(u) r8c9#6(U)

Chain 23: r3c9#3(w) r8c9#3(W)

Chain 25: r9c8#5(y) r9c9#5(Y)

(again, a different chain definition)

So there are some, anyway.