Analysis of xx-top500-202-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .56...2.....47....3...1.....1.....6....6..8..7..........82.....2.......7.......1. initial

Autosolve

position: 1568..2749824761..34751269881..2.76..2.6.78.176.1...2..782.1..62.1.6..876..7...12 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # E5: 3,9 => SOL
* DIS # E5: 4,5 => CTR => E5: 3,9
* DIS # E6: 3,9 => CTR => E6: 4,5,8
* DIS # E7: 3,9 => CTR => E7: 4,5
* PRF # E7: 4,5 => SOL
* DIS # E9: 3,9 => CTR => E9: 4,5,8
* DIS # F4: 3,9 => CTR => F4: 4,5
* DIS # F6: 3,9 => CTR => F6: 4,5,8
* PRF # F9: 3,9 => SOL
* DIS # H5: 3,5 => CTR => H5: 4
* PRF # H5: 4 => SOL
* PRF # H7: 3,5 => SOL
* DIS # H7: 4 => CTR => H7: 3,5
* DIS # C5: 4,5 => CTR => C5: 3,9
* DIS # C6: 4,5 => CTR => C6: 3,9
* DIS # E5: 4,5 => CTR => E5: 3,9
* PRF # E5: 3,9 => SOL
* PRF # H5: 4,5 => SOL
* DIS # H5: 3 => CTR => H5: 4,5
* DIS # F4: 3,9 => CTR => F4: 4,5
* PRF # E5: 3,9 => SOL
* DIS # E5: 4,5 => CTR => E5: 3,9
* DIS # E6: 3,9 => CTR => E6: 4,5,8
* DIS # F6: 3,9 => CTR => F6: 4,5,8
* DIS # C4: 3,9 => CTR => C4: 4,5
* PRF # E7: 4,5 => SOL
* DIS # E7: 3,9 => CTR => E7: 4,5
* DIS # G7: 4,5 => CTR => G7: 3,9
* DIS # H7: 4,5 => CTR => H7: 3
* PRF # H7: 3 => SOL
* DIS # E9: 3,9 => CTR => E9: 4,5,8
* PRF # F9: 3,9 => SOL
* DIS # G9: 3,9 => CTR => G9: 4,5
* PRF # G9: 4,5 => SOL
* DIS # E9: 4,5 => CTR => E9: 3,8,9
* DIS # F9: 4,5 => CTR => F9: 3,8,9
* PRF # G9: 4,5 => SOL
* DIS # G9: 3,9 => CTR => G9: 4,5
* DIS # C5: 4,5 => CTR => C5: 3,9
* DIS # C6: 4,5 => CTR => C6: 3,9
* DIS # E7: 3,9 => CTR => E7: 4,5
* PRF # E7: 4,5 => SOL
* DIS # E9: 3,9 => CTR => E9: 4,5,8
* PRF # F9: 3,9 => SOL
* PRF # E7: 4,5 => SOL
* DIS # E7: 3,9 => CTR => E7: 4,5
* DIS # E9: 4,5 => CTR => E9: 3,8,9
* DIS # F9: 4,5 => CTR => F9: 3,8,9
* DIS # F6: 4,5 => CTR => F6: 3,8,9
* DIS # G7: 4,5 => CTR => G7: 3,9
* DIS # H7: 4,5 => CTR => H7: 3
* PRF # H7: 3 => SOL
* PRF # G9: 4,5 => SOL
* DIS # G9: 3,9 => CTR => G9: 4,5
* DIS # G6: 4,5 => CTR => G6: 3
* PRF # G6: 3 => SOL
* CNT  56 HDP CHAINS /  86 HYP OPENED

See Appendix: Full HDP Chains for full list of HDP chains.

Pair Reduction

Pair Reduction

The following important HDP chains were detected:

* PRF # E5: 3,9 => SOL
* STA E5: 3,9
* CNT   1 HDP CHAINS /   1 HYP OPENED

See Appendix: Full HDP Chains for full list of HDP chains.

Details

Positions

.56...2.....47....3...1.....1.....6....6..8..7..........82.....2.......7.......1. initial
1568..2749824761..34751269881..2.76..2.6.78.176.1...2..782.1..62.1.6..876..7...12 autosolve
156839274982476153347512698814325769523697841769148325478251936231964587695783412 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (13)
E1: 3,9
F1: 3,9
H2: 3,5
I2: 3,5
A5: 4,5
D4: 3,9
A7: 4,5
B8: 3,9
B9: 3,9
C9: 4,5
D8: 3,9
F8: 4,5
G8: 4,5

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
E1,F1: 3.. / E1 = 3  => 11 pairs (_) / F1 = 3  => 11 pairs (_)
H2,I2: 3.. / H2 = 3  =>  0 pairs (X) / I2 = 3  => 16 pairs (_)
B8,B9: 3.. / B8 = 3  => 10 pairs (_) / B9 = 3  => 10 pairs (_)
B8,D8: 3.. / B8 = 3  => 10 pairs (_) / D8 = 3  => 10 pairs (_)
D4,D8: 3.. / D4 = 3  => 10 pairs (_) / D8 = 3  => 10 pairs (_)
H5,G6: 4.. / H5 = 4  =>  0 pairs (*) / G6 = 4  =>  0 pairs (X)
A7,C9: 4.. / A7 = 4  =>  0 pairs (*) / C9 = 4  =>  0 pairs (X)
C4,F4: 4.. / C4 = 4  =>  0 pairs (*) / F4 = 4  =>  0 pairs (X)
F8,G8: 4.. / F8 = 4  =>  0 pairs (*) / G8 = 4  =>  0 pairs (X)
A5,A7: 4.. / A5 = 4  =>  0 pairs (X) / A7 = 4  =>  0 pairs (_)
H5,H7: 4.. / H5 = 4  =>  0 pairs (*) / H7 = 4  =>  0 pairs (X)
H2,I2: 5.. / H2 = 5  => 16 pairs (_) / I2 = 5  =>  0 pairs (X)
A7,C9: 5.. / A7 = 5  =>  0 pairs (X) / C9 = 5  =>  0 pairs (_)
F8,G8: 5.. / F8 = 5  =>  0 pairs (X) / G8 = 5  =>  0 pairs (_)
A5,A7: 5.. / A5 = 5  =>  0 pairs (*) / A7 = 5  =>  0 pairs (X)
E6,F6: 8.. / E6 = 8  => 13 pairs (_) / F6 = 8  => 13 pairs (_)
E9,F9: 8.. / E9 = 8  => 13 pairs (_) / F9 = 8  => 13 pairs (_)
E6,E9: 8.. / E6 = 8  => 13 pairs (_) / E9 = 8  => 13 pairs (_)
F6,F9: 8.. / F6 = 8  => 13 pairs (_) / F9 = 8  => 13 pairs (_)
E1,F1: 9.. / E1 = 9  => 11 pairs (_) / F1 = 9  => 11 pairs (_)
I4,I6: 9.. / I4 = 9  => 16 pairs (_) / I6 = 9  => 14 pairs (_)
B8,B9: 9.. / B8 = 9  => 10 pairs (_) / B9 = 9  => 10 pairs (_)
G7,G9: 9.. / G7 = 9  => 13 pairs (_) / G9 = 9  =>  0 pairs (X)
C5,E5: 9.. / C5 = 9  => 13 pairs (_) / E5 = 9  =>  0 pairs (*)
E7,G7: 9.. / E7 = 9  =>  0 pairs (X) / G7 = 9  => 13 pairs (_)
B8,D8: 9.. / B8 = 9  => 10 pairs (_) / D8 = 9  => 10 pairs (_)
D4,D8: 9.. / D4 = 9  => 10 pairs (_) / D8 = 9  => 10 pairs (_)
* DURATION: 0:00:44.791235  START: 09:41:24.024127  END: 09:42:08.815362 2017-05-04
* CP COUNT: (27)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A5,A7,B8,B9,C9,D4,D8,E1,F1,F8,G8,H2,I2)
* 1568..2749824761..34751269881..2.76..2.6.78.176.1...2..782.1..62.1.6..876..7...12
* PAIR E1: 3,9 COL E
E5: 3,9,4,5                              # reduction candidate for 3,9
E5: 3,9 => SOLVED
* 156839274982476153347512698814325769523697841769148325478251936231964587695783412
E5: 4,5 => CTR
* 1568..2749824761..34751269881..2.76..296.783176.1..42..782.1.462.1.645876.47...12
E6: 3,9,4,5,8                            # reduction candidate for 3,9
E6: 3,9 => CTR
* 1568..2749824761..34751269881..2.76..296.783176.1.842..782.1..62.1.6..876..78..12
E6: 4,5,8                                # 13 pairs
E7: 3,9,4,5                              # reduction candidate for 3,9
E7: 3,9 => CTR
* 1568..2749824761..34751269881..2.76..296.783176.1..42..782.1.462.1.645876.47...12
E7: 4,5 => SOLVED
* 156839274982476153347512698814325769523697841769148325478251936231964587695783412
E9: 3,9,4,5,8                            # reduction candidate for 3,9
E9: 3,9 => CTR
* 1568..2749824761..34751269881..2.76..296.78.176.18..2..782.1..62.1.6..876..7.8.12
E9: 4,5,8                                # 13 pairs
* PAIR F1: 3,9 COL F
F4: 3,9,4,5                              # reduction candidate for 3,9
F4: 3,9 => CTR
* 1568..274982476153347512698814.2.7655296.78417631...294782.1..62.1.6..876.57...12
F4: 4,5                                  # 14 pairs
F6: 3,9,4,5,8                            # reduction candidate for 3,9
F6: 3,9 => CTR
* 1568..2749824761..34751269881..2.76..296.783176.18.42..782.1.462.1.645876.4758.12
F6: 4,5,8                                # 13 pairs
F9: 3,9,4,5,8                            # reduction candidate for 3,9
F9: 3,9 => SOLVED
* 156839274982476153347512698814325769523697841769148325478251936231964587695783412
F9: 4,5,8                                # 13 pairs
* PAIR H2: 3,5 COL H
H5: 3,5,4                                # reduction candidate for 3,5
H5: 3,5 => CTR
* 1568..2749824761..34751269881..2.76..2.6.78.176.1..42..782.1.462.1.645876.47...12
H5: 4 => SOLVED
* 156839274982476153347512698814325769523697841769148325478251936231964587695783412
H7: 3,5,4                                # reduction candidate for 3,5
H7: 3,5 => SOLVED
* 156839274982476153347512698814325769523697841769148325478251936231964587695783412
H7: 4 => CTR
* 1568..2749824761..34751269881..2.76..2.6.78.176.1...2..782.1.462.1.645876.47...12
* PAIR I2: 3,5 COL I
I4: 3,5,9                                # reduction candidate for 3,5
I4: 3,5                                  # 14 pairs
I6: 3,5,9                                # reduction candidate for 3,5
I6: 3,5                                  # 16 pairs
* PAIR A5: 4,5 BLK 4
C4: 4,5,3,9                              # reduction candidate for 4,5
C4: 4,5                                  # 16 pairs
C5: 4,5,3,9                              # reduction candidate for 4,5
C5: 4,5 => CTR
* 1568..2749824761..34751269881..2.76..2.69783176.1..42..782.19462.19645876947..312
C5: 3,9                                  # 14 pairs
C6: 4,5,3,9                              # reduction candidate for 4,5
C6: 4,5 => CTR
* 1568..27498247615334751269881..24765.2.6.78417641583294782.15362.1.654876.57...12
C6: 3,9                                  # 14 pairs
* PAIR A5: 4,5 ROW 5
E5: 4,5,3,9                              # reduction candidate for 4,5
E5: 4,5 => CTR
* 1568..2749824761..34751269881..2.76..296.783176.1..42..782.1.462.1.645876.47...12
E5: 3,9 => SOLVED
* 156839274982476153347512698814325769523697841769148325478251936231964587695783412
H5: 4,5,3                                # reduction candidate for 4,5
H5: 4,5 => SOLVED
* 156839274982476153347512698814325769523697841769148325478251936231964587695783412
H5: 3 => CTR
* 1568..2749824761..34751269881..2.76..2.6.783176.1..42..782.1.462.1.645876.47...12
* PAIR D4: 3,9 BLK 5
F4: 3,9,4,5                              # reduction candidate for 3,9
F4: 3,9 => CTR
* 1568..274982476153347512698814.2.7655296.78417631...294782.1..62.1.6..876.57...12
F4: 4,5                                  # 14 pairs
E5: 3,9,4,5                              # reduction candidate for 3,9
E5: 3,9 => SOLVED
* 156839274982476153347512698814325769523697841769148325478251936231964587695783412
E5: 4,5 => CTR
* 1568..2749824761..34751269881..2.76..296.783176.1..42..782.1.462.1.645876.47...12
E6: 3,9,4,5,8                            # reduction candidate for 3,9
E6: 3,9 => CTR
* 1568..2749824761..34751269881..2.76..296.783176.1.842..782.1..62.1.6..876..78..12
E6: 4,5,8                                # 13 pairs
F6: 3,9,4,5,8                            # reduction candidate for 3,9
F6: 3,9 => CTR
* 1568..2749824761..34751269881..2.76..296.783176.18.42..782.1.462.1.645876.4758.12
F6: 4,5,8                                # 13 pairs
* PAIR D4: 3,9 ROW 4
C4: 3,9,4,5                              # reduction candidate for 3,9
C4: 3,9 => CTR
* 1568..27498247615334751269881..24765.2.6.78417641583294782.15362.1.654876.57...12
C4: 4,5                                  # 16 pairs
I4: 3,9,5                                # reduction candidate for 3,9
I4: 3,9                                  # 18 pairs
* PAIR A7: 4,5 ROW 7
E7: 4,5,3,9                              # reduction candidate for 4,5
E7: 4,5 => SOLVED
* 156839274982476153347512698814325769523697841769148325478251936231964587695783412
E7: 3,9 => CTR
* 1568..2749824761..34751269881..2.76..296.783176.1..42..782.1.462.1.645876.47...12
G7: 4,5,3,9                              # reduction candidate for 4,5
G7: 4,5 => CTR
* 15683927498247615334751269881.92.765.2.6.78.176.1...2..78291.3629136..8763.7..912
G7: 3,9                                  # 14 pairs
H7: 4,5,3                                # reduction candidate for 4,5
H7: 4,5 => CTR
* 1568..2749824761..34751269881..2.76..296.783176.1..42..782.1.462.1.645876.47...12
H7: 3 => SOLVED
* 156839274982476153347512698814325769523697841769148325478251936231964587695783412
* PAIR B9: 3,9 ROW 9
E9: 3,9,4,5,8                            # reduction candidate for 3,9
E9: 3,9 => CTR
* 1568..2749824761..34751269881..2.76..296.78.176.18..2..782.1..62.1.6..876..7.8.12
E9: 4,5,8                                # 13 pairs
F9: 3,9,4,5,8                            # reduction candidate for 3,9
F9: 3,9 => SOLVED
* 156839274982476153347512698814325769523697841769148325478251936231964587695783412
F9: 4,5,8                                # 13 pairs
G9: 3,9,4,5                              # reduction candidate for 3,9
G9: 3,9 => CTR
* 1568..2749824761..34751269881..2.76..296.783176.1..42..782.1.462.1.645876.47...12
G9: 4,5 => SOLVED
* 156839274982476153347512698814325769523697841769148325478251936231964587695783412
* PAIR C9: 4,5 ROW 9
E9: 4,5,3,8,9                            # reduction candidate for 4,5
E9: 4,5 => CTR
* 1568..2749824761..34751269881..2.76..296.783176.18.42..782.1.462.1.645876.4758.12
E9: 3,8,9                                # 13 pairs
F9: 4,5,3,8,9                            # reduction candidate for 4,5
F9: 4,5 => CTR
* 1568..2749824761..347512698814.2.7655296478317631584294782.1.562.1.6..876..78..12
F9: 3,8,9                                # 13 pairs
G9: 4,5,3,9                              # reduction candidate for 4,5
G9: 4,5 => SOLVED
* 156839274982476153347512698814325769523697841769148325478251936231964587695783412
G9: 3,9 => CTR
* 1568..2749824761..34751269881..2.76..296.783176.1..42..782.1.462.1.645876.47...12
* PAIR C9: 4,5 COL C
C4: 4,5,3,9                              # reduction candidate for 4,5
C4: 4,5                                  # 16 pairs
C5: 4,5,3,9                              # reduction candidate for 4,5
C5: 4,5 => CTR
* 1568..2749824761..34751269881..2.76..2.69783176.1..42..782.19462.19645876947..312
C5: 3,9                                  # 14 pairs
C6: 4,5,3,9                              # reduction candidate for 4,5
C6: 4,5 => CTR
* 1568..27498247615334751269881..24765.2.6.78417641583294782.15362.1.654876.57...12
C6: 3,9                                  # 14 pairs
* PAIR D8: 3,9 BLK 8
E7: 3,9,4,5                              # reduction candidate for 3,9
E7: 3,9 => CTR
* 1568..2749824761..34751269881..2.76..296.783176.1..42..782.1.462.1.645876.47...12
E7: 4,5 => SOLVED
* 156839274982476153347512698814325769523697841769148325478251936231964587695783412
E9: 3,9,4,5,8                            # reduction candidate for 3,9
E9: 3,9 => CTR
* 1568..2749824761..34751269881..2.76..296.78.176.18..2..782.1..62.1.6..876..7.8.12
E9: 4,5,8                                # 13 pairs
F9: 3,9,4,5,8                            # reduction candidate for 3,9
F9: 3,9 => SOLVED
* 156839274982476153347512698814325769523697841769148325478251936231964587695783412
F9: 4,5,8                                # 13 pairs
* PAIR F8: 4,5 BLK 8
E7: 4,5,3,9                              # reduction candidate for 4,5
E7: 4,5 => SOLVED
* 156839274982476153347512698814325769523697841769148325478251936231964587695783412
E7: 3,9 => CTR
* 1568..2749824761..34751269881..2.76..296.783176.1..42..782.1.462.1.645876.47...12
E9: 4,5,3,8,9                            # reduction candidate for 4,5
E9: 4,5 => CTR
* 1568..2749824761..34751269881..2.76..296.783176.18.42..782.1.462.1.645876.4758.12
E9: 3,8,9                                # 13 pairs
F9: 4,5,3,8,9                            # reduction candidate for 4,5
F9: 4,5 => CTR
* 1568..2749824761..347512698814.2.7655296478317631584294782.1.562.1.6..876..78..12
F9: 3,8,9                                # 13 pairs
* PAIR F8: 4,5 COL F
F4: 4,5,3,9                              # reduction candidate for 4,5
F4: 4,5                                  # 14 pairs
F6: 4,5,3,8,9                            # reduction candidate for 4,5
F6: 4,5 => CTR
* 1568..2749824761..347512698814.2.76552.6.78.176.1854294782.1..62.1.645876.57.8.12
F6: 3,8,9                                # 13 pairs
* PAIR G8: 4,5 BLK 9
G7: 4,5,3,9                              # reduction candidate for 4,5
G7: 4,5 => CTR
* 15683927498247615334751269881.92.765.2.6.78.176.1...2..78291.3629136..8763.7..912
G7: 3,9                                  # 14 pairs
H7: 4,5,3                                # reduction candidate for 4,5
H7: 4,5 => CTR
* 1568..2749824761..34751269881..2.76..296.783176.1..42..782.1.462.1.645876.47...12
H7: 3 => SOLVED
* 156839274982476153347512698814325769523697841769148325478251936231964587695783412
G9: 4,5,3,9                              # reduction candidate for 4,5
G9: 4,5 => SOLVED
* 156839274982476153347512698814325769523697841769148325478251936231964587695783412
G9: 3,9 => CTR
* 1568..2749824761..34751269881..2.76..296.783176.1..42..782.1.462.1.645876.47...12
* PAIR G8: 4,5 COL G
G6: 4,5,3                                # reduction candidate for 4,5
G6: 4,5 => CTR
* 1568..2749824761..34751269881..2.76..296.783176.1..42..782.1.462.1.645876.47...12
G6: 3 => SOLVED
* 156839274982476153347512698814325769523697841769148325478251936231964587695783412
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-202-base-pr-000.dot
* REASONING
* PRF # E5: 3,9 => SOL
* DIS # E5: 4,5 => CTR => E5: 3,9
* DIS # E6: 3,9 => CTR => E6: 4,5,8
* DIS # E7: 3,9 => CTR => E7: 4,5
* PRF # E7: 4,5 => SOL
* DIS # E9: 3,9 => CTR => E9: 4,5,8
* DIS # F4: 3,9 => CTR => F4: 4,5
* DIS # F6: 3,9 => CTR => F6: 4,5,8
* PRF # F9: 3,9 => SOL
* DIS # H5: 3,5 => CTR => H5: 4
* PRF # H5: 4 => SOL
* PRF # H7: 3,5 => SOL
* DIS # H7: 4 => CTR => H7: 3,5
* DIS # C5: 4,5 => CTR => C5: 3,9
* DIS # C6: 4,5 => CTR => C6: 3,9
* DIS # E5: 4,5 => CTR => E5: 3,9
* PRF # E5: 3,9 => SOL
* PRF # H5: 4,5 => SOL
* DIS # H5: 3 => CTR => H5: 4,5
* DIS # F4: 3,9 => CTR => F4: 4,5
* PRF # E5: 3,9 => SOL
* DIS # E5: 4,5 => CTR => E5: 3,9
* DIS # E6: 3,9 => CTR => E6: 4,5,8
* DIS # F6: 3,9 => CTR => F6: 4,5,8
* DIS # C4: 3,9 => CTR => C4: 4,5
* PRF # E7: 4,5 => SOL
* DIS # E7: 3,9 => CTR => E7: 4,5
* DIS # G7: 4,5 => CTR => G7: 3,9
* DIS # H7: 4,5 => CTR => H7: 3
* PRF # H7: 3 => SOL
* DIS # E9: 3,9 => CTR => E9: 4,5,8
* PRF # F9: 3,9 => SOL
* DIS # G9: 3,9 => CTR => G9: 4,5
* PRF # G9: 4,5 => SOL
* DIS # E9: 4,5 => CTR => E9: 3,8,9
* DIS # F9: 4,5 => CTR => F9: 3,8,9
* PRF # G9: 4,5 => SOL
* DIS # G9: 3,9 => CTR => G9: 4,5
* DIS # C5: 4,5 => CTR => C5: 3,9
* DIS # C6: 4,5 => CTR => C6: 3,9
* DIS # E7: 3,9 => CTR => E7: 4,5
* PRF # E7: 4,5 => SOL
* DIS # E9: 3,9 => CTR => E9: 4,5,8
* PRF # F9: 3,9 => SOL
* PRF # E7: 4,5 => SOL
* DIS # E7: 3,9 => CTR => E7: 4,5
* DIS # E9: 4,5 => CTR => E9: 3,8,9
* DIS # F9: 4,5 => CTR => F9: 3,8,9
* DIS # F6: 4,5 => CTR => F6: 3,8,9
* DIS # G7: 4,5 => CTR => G7: 3,9
* DIS # H7: 4,5 => CTR => H7: 3
* PRF # H7: 3 => SOL
* PRF # G9: 4,5 => SOL
* DIS # G9: 3,9 => CTR => G9: 4,5
* DIS # G6: 4,5 => CTR => G6: 3
* PRF # G6: 3 => SOL
* CNT  56 HDP CHAINS /  86 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A5,A7,B8,B9,C9,D4,D8,E1,F1,F8,G8,H2,I2)
* 1568..2749824761..34751269881..2.76..2.6.78.176.1...2..782.1..62.1.6..876..7...12
* PAIR E1: 3,9 COL E
E5: 3,9,4,5                              # reduction candidate for 3,9
E5: 3,9 => SOLVED
* 156839274982476153347512698814325769523697841769148325478251936231964587695783412
* DURATION: 0:00:02.158482  START: 09:43:33.671104  END: 09:43:35.829586 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-202-base-pr-001.dot
* REASONING
* PRF # E5: 3,9 => SOL
* STA E5: 3,9
* CNT   1 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 202

solution: 156839274982476153347512698814325769523697841769148325478251936231964587695783412
info: 1891     FNBTHWX  S8.f     42691

http://www.sfsudoku.com/su17ExtremeDiff500.txt from http://www.minimumsudoku.com/

Solution

position: 156839274982476153347512698814325769523697841769148325478251936231964587695783412 solved
Solution

See section Pair Reduction for the HDP chains leading to this result.

Appendix: Full HDP Chains

A1. Pair Reduction Analysis

Full list of HDP chains traversed:

* PRF # E5: 3,9 => SOL
* DIS # E5: 4,5 => CTR => E5: 3,9
* DIS # E6: 3,9 => CTR => E6: 4,5,8
* INC # E6: 4,5,8 => UNS
* DIS # E7: 3,9 => CTR => E7: 4,5
* PRF # E7: 4,5 => SOL
* DIS # E9: 3,9 => CTR => E9: 4,5,8
* INC # E9: 4,5,8 => UNS
* DIS # F4: 3,9 => CTR => F4: 4,5
* INC # F4: 4,5 => UNS
* DIS # F6: 3,9 => CTR => F6: 4,5,8
* INC # F6: 4,5,8 => UNS
* PRF # F9: 3,9 => SOL
* INC # F9: 4,5,8 => UNS
* DIS # H5: 3,5 => CTR => H5: 4
* PRF # H5: 4 => SOL
* PRF # H7: 3,5 => SOL
* DIS # H7: 4 => CTR => H7: 3,5
* INC # I4: 3,5 => UNS
* INC # I6: 3,5 => UNS
* INC # C4: 4,5 => UNS
* DIS # C5: 4,5 => CTR => C5: 3,9
* INC # C5: 3,9 => UNS
* DIS # C6: 4,5 => CTR => C6: 3,9
* INC # C6: 3,9 => UNS
* DIS # E5: 4,5 => CTR => E5: 3,9
* PRF # E5: 3,9 => SOL
* PRF # H5: 4,5 => SOL
* DIS # H5: 3 => CTR => H5: 4,5
* DIS # F4: 3,9 => CTR => F4: 4,5
* INC # F4: 4,5 => UNS
* PRF # E5: 3,9 => SOL
* DIS # E5: 4,5 => CTR => E5: 3,9
* DIS # E6: 3,9 => CTR => E6: 4,5,8
* INC # E6: 4,5,8 => UNS
* DIS # F6: 3,9 => CTR => F6: 4,5,8
* INC # F6: 4,5,8 => UNS
* DIS # C4: 3,9 => CTR => C4: 4,5
* INC # C4: 4,5 => UNS
* INC # I4: 3,9 => UNS
* PRF # E7: 4,5 => SOL
* DIS # E7: 3,9 => CTR => E7: 4,5
* DIS # G7: 4,5 => CTR => G7: 3,9
* INC # G7: 3,9 => UNS
* DIS # H7: 4,5 => CTR => H7: 3
* PRF # H7: 3 => SOL
* DIS # E9: 3,9 => CTR => E9: 4,5,8
* INC # E9: 4,5,8 => UNS
* PRF # F9: 3,9 => SOL
* INC # F9: 4,5,8 => UNS
* DIS # G9: 3,9 => CTR => G9: 4,5
* PRF # G9: 4,5 => SOL
* DIS # E9: 4,5 => CTR => E9: 3,8,9
* INC # E9: 3,8,9 => UNS
* DIS # F9: 4,5 => CTR => F9: 3,8,9
* INC # F9: 3,8,9 => UNS
* PRF # G9: 4,5 => SOL
* DIS # G9: 3,9 => CTR => G9: 4,5
* INC # C4: 4,5 => UNS
* DIS # C5: 4,5 => CTR => C5: 3,9
* INC # C5: 3,9 => UNS
* DIS # C6: 4,5 => CTR => C6: 3,9
* INC # C6: 3,9 => UNS
* DIS # E7: 3,9 => CTR => E7: 4,5
* PRF # E7: 4,5 => SOL
* DIS # E9: 3,9 => CTR => E9: 4,5,8
* INC # E9: 4,5,8 => UNS
* PRF # F9: 3,9 => SOL
* INC # F9: 4,5,8 => UNS
* PRF # E7: 4,5 => SOL
* DIS # E7: 3,9 => CTR => E7: 4,5
* DIS # E9: 4,5 => CTR => E9: 3,8,9
* INC # E9: 3,8,9 => UNS
* DIS # F9: 4,5 => CTR => F9: 3,8,9
* INC # F9: 3,8,9 => UNS
* INC # F4: 4,5 => UNS
* DIS # F6: 4,5 => CTR => F6: 3,8,9
* INC # F6: 3,8,9 => UNS
* DIS # G7: 4,5 => CTR => G7: 3,9
* INC # G7: 3,9 => UNS
* DIS # H7: 4,5 => CTR => H7: 3
* PRF # H7: 3 => SOL
* PRF # G9: 4,5 => SOL
* DIS # G9: 3,9 => CTR => G9: 4,5
* DIS # G6: 4,5 => CTR => G6: 3
* PRF # G6: 3 => SOL
* CNT  86 HDP CHAINS /  86 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* PRF # E5: 3,9 => SOL
* STA E5: 3,9
* CNT   1 HDP CHAINS /   1 HYP OPENED