Analysis of zz-www.sudokuoftheday.co.uk-20190129-absurd-base.sdk

Contents

Sudoku from http://www.sudokuoftheday.co.uk/cgi-bin/sudoku1280.cgi?ACTION=archive2&USER=&MONTH=Jan&YEAR=2019

level: medium

Sudoku from http://www.sudokuoftheday.co.uk/cgi-bin/sudoku1280.cgi?ACTION=archive2&USER=&MONTH=Jan&YEAR=2019

position: .......6...5..4.92.2..5..8..8...2..39....1.46..7..9..1...9....545..........71.... initial

Autosolve

position: ...29.567..5..4.92.29.57.84.8...29.39325.1.46..7..9..1...94...545..2...9.9.7154.8 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # C1: 3,8 => CTR => C1: 1,4
* PRF # A2: 6,7 => SOL
* DIS # A2: 3,8 => CTR => A2: 6,7
* DIS # A2: 3,6 => CTR => A2: 7,8
* DIS # D3: 1 => CTR => D3: 3,6
* DIS # A9: 3,6 => CTR => A9: 2
* DIS # D2: 3,8 => CTR => D2: 1,6
* PRF # E2: 3,8 => SOL
* DIS # E2: 6 => CTR => E2: 3,8
* DIS # C1: 3,8 => CTR => C1: 1,4
* PRF # F7: 3,8 => SOL
* DIS # F7: 6 => CTR => F7: 3,8
* DIS # F8: 3,8 => CTR => F8: 6
* PRF # F8: 6 => SOL
* DIS # D2: 6,8 => CTR => D2: 1,3
* DIS # D3: 1,3 => CTR => D3: 6
* PRF # D3: 6 => SOL
* PRF # A4: 5,6 => SOL
* DIS # A4: 1 => CTR => A4: 5,6
* DIS # C4: 4,6 => CTR => C4: 1
* PRF # C4: 1 => SOL
* DIS # D6: 4,6 => CTR => D6: 3,8
* PRF # D6: 3,8 => SOL
* DIS # D6: 4,6 => CTR => D6: 3,8
* PRF # D6: 3,8 => SOL
* DIS # C4: 4,6 => CTR => C4: 1
* PRF # C4: 1 => SOL
* PRF # A7: 1,7 => SOL
* DIS # A7: 2,3,8 => CTR => A7: 1,7
* DIS # A9: 3,6 => CTR => A9: 2
* PRF # F7: 3,8 => SOL
* DIS # F7: 6 => CTR => F7: 3,8
* DIS # F8: 3,8 => CTR => F8: 6
* PRF # F8: 6 => SOL
* PRF # C8: 3,8 => SOL
* DIS # C8: 1 => CTR => C8: 3,8
* DIS # D2: 3,8 => CTR => D2: 1,6
* PRF # D6: 3,8 => SOL
* DIS # D6: 4,6 => CTR => D6: 3,8
* PRF # H7: 2,3 => SOL
* DIS # H7: 1 => CTR => H7: 2,3
* DIS # A9: 6 => CTR => A9: 2,3
* CNT  42 HDP CHAINS /  53 HYP OPENED

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

Pair Reduction

Pair Reduction

The following important HDP chains were detected:

* DIS # C1: 3,8 => CTR => C1: 1,4
* PRF C1: 1,4 # A2: 6,7 => SOL
* STA C1: 1,4 + A2: 6,7
* CNT   2 HDP CHAINS /   3 HYP OPENED

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

Details

Positions

.......6...5..4.92.2..5..8..8...2..39....1.46..7..9..1...9....545..........71.... initial
...29.567..5..4.92.29.57.84.8...29.39325.1.46..7..9..1...94...545..2...9.9.7154.8 autosolve
814293567765184392329657184581462973932571846647839251173948625458326719296715438 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (21)
B1: 1,4
B2: 6,7
A3: 3,6
F1: 3,8
G2: 1,3
G3: 1,3
A6: 5,6
B6: 4,6
D4: 4,6
E4: 6,7
E5: 7,8
H4: 5,7
G5: 7,8
G6: 2,8
H6: 2,5
B7: 1,7
C9: 3,6
D8: 3,8
G7: 2,6
G8: 6,7
H9: 2,3

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
D2,D3: 1.. / D2 = 1  => 21 pairs (_) / D3 = 1  =>  0 pairs (X)
G2,G3: 1.. / G2 = 1  =>  0 pairs (X) / G3 = 1  => 21 pairs (_)
A4,C4: 1.. / A4 = 1  =>  0 pairs (X) / C4 = 1  =>  0 pairs (_)
H7,H8: 1.. / H7 = 1  =>  0 pairs (X) / H8 = 1  =>  0 pairs (_)
D2,G2: 1.. / D2 = 1  => 21 pairs (_) / G2 = 1  =>  0 pairs (X)
D3,G3: 1.. / D3 = 1  =>  0 pairs (X) / G3 = 1  => 21 pairs (_)
C8,H8: 1.. / C8 = 1  =>  0 pairs (X) / H8 = 1  =>  0 pairs (_)
B1,B7: 1.. / B1 = 1  =>  0 pairs (*) / B7 = 1  =>  0 pairs (X)
G6,H6: 2.. / G6 = 2  =>  0 pairs (*) / H6 = 2  =>  0 pairs (X)
A7,A9: 2.. / A7 = 2  =>  0 pairs (X) / A9 = 2  => 22 pairs (_)
A9,H9: 2.. / A9 = 2  => 22 pairs (_) / H9 = 2  =>  0 pairs (X)
G6,G7: 2.. / G6 = 2  =>  0 pairs (*) / G7 = 2  =>  0 pairs (X)
G2,G3: 3.. / G2 = 3  => 21 pairs (_) / G3 = 3  =>  0 pairs (X)
D6,E6: 3.. / D6 = 3  =>  0 pairs (X) / E6 = 3  => 22 pairs (_)
E2,E6: 3.. / E2 = 3  =>  0 pairs (X) / E6 = 3  => 22 pairs (_)
B1,C1: 4.. / B1 = 4  =>  0 pairs (X) / C1 = 4  =>  0 pairs (_)
C4,B6: 4.. / C4 = 4  =>  0 pairs (X) / B6 = 4  =>  0 pairs (_)
D4,D6: 4.. / D4 = 4  =>  0 pairs (*) / D6 = 4  =>  0 pairs (X)
C4,D4: 4.. / C4 = 4  =>  0 pairs (X) / D4 = 4  =>  0 pairs (_)
B6,D6: 4.. / B6 = 4  =>  0 pairs (*) / D6 = 4  =>  0 pairs (X)
B1,B6: 4.. / B1 = 4  =>  0 pairs (X) / B6 = 4  =>  0 pairs (_)
C1,C4: 4.. / C1 = 4  =>  0 pairs (*) / C4 = 4  =>  0 pairs (X)
A4,A6: 5.. / A4 = 5  =>  0 pairs (*) / A6 = 5  =>  0 pairs (X)
H4,H6: 5.. / H4 = 5  =>  0 pairs (X) / H6 = 5  =>  0 pairs (_)
A4,H4: 5.. / A4 = 5  =>  0 pairs (*) / H4 = 5  =>  0 pairs (X)
A6,H6: 5.. / A6 = 5  =>  0 pairs (X) / H6 = 5  =>  0 pairs (_)
A9,C9: 6.. / A9 = 6  =>  0 pairs (X) / C9 = 6  => 22 pairs (_)
F7,F8: 6.. / F7 = 6  =>  0 pairs (X) / F8 = 6  =>  0 pairs (_)
G7,G8: 6.. / G7 = 6  =>  0 pairs (*) / G8 = 6  =>  0 pairs (X)
A3,D3: 6.. / A3 = 6  =>  0 pairs (X) / D3 = 6  =>  0 pairs (_)
F7,G7: 6.. / F7 = 6  =>  0 pairs (X) / G7 = 6  =>  0 pairs (_)
F8,G8: 6.. / F8 = 6  =>  0 pairs (*) / G8 = 6  =>  0 pairs (X)
B2,B6: 6.. / B2 = 6  =>  0 pairs (*) / B6 = 6  =>  0 pairs (X)
C4,C9: 6.. / C4 = 6  =>  0 pairs (X) / C9 = 6  => 22 pairs (_)
A2,B2: 7.. / A2 = 7  =>  0 pairs (*) / B2 = 7  =>  0 pairs (X)
E4,E5: 7.. / E4 = 7  =>  0 pairs (X) / E5 = 7  =>  0 pairs (_)
H4,G5: 7.. / H4 = 7  =>  0 pairs (*) / G5 = 7  =>  0 pairs (X)
A7,B7: 7.. / A7 = 7  =>  0 pairs (X) / B7 = 7  =>  0 pairs (_)
G8,H8: 7.. / G8 = 7  =>  0 pairs (*) / H8 = 7  =>  0 pairs (X)
E4,H4: 7.. / E4 = 7  =>  0 pairs (X) / H4 = 7  =>  0 pairs (_)
E5,G5: 7.. / E5 = 7  =>  0 pairs (*) / G5 = 7  =>  0 pairs (X)
A2,A7: 7.. / A2 = 7  =>  0 pairs (*) / A7 = 7  =>  0 pairs (X)
B2,B7: 7.. / B2 = 7  =>  0 pairs (X) / B7 = 7  =>  0 pairs (_)
G5,G8: 7.. / G5 = 7  =>  0 pairs (X) / G8 = 7  =>  0 pairs (_)
H4,H8: 7.. / H4 = 7  =>  0 pairs (*) / H8 = 7  =>  0 pairs (X)
G5,G6: 8.. / G5 = 8  =>  0 pairs (*) / G6 = 8  =>  0 pairs (X)
E5,G5: 8.. / E5 = 8  =>  0 pairs (X) / G5 = 8  =>  0 pairs (_)
* DURATION: 0:01:02.072677  START: 03:17:46.899481  END: 03:18:48.972158 2019-05-01
* CP COUNT: (47)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A3,A6,B1,B2,B6,B7,C9,D4,D8,E4,E5,F1,G2,G3,G5,G6,G7,G8,H4,H6,H9)
* ...29.567..5..4.92.29.57.84.8...29.39325.1.46..7..9..1...94...545..2...9.9.7154.8
* PAIR B1: 1,4 BLK 1
C1: 1,4,3,8                              # reduction candidate for 1,4
C1: 3,8 => CTR
* .4.29.567..5..4.92.29.57.84.84672953932581746567439821.1.94.2.545..2...9.9.7154.8
C1: 1,4                                  # 24 pairs
* PAIR B2: 6,7 BLK 1
A2: 6,7,3,8                              # reduction candidate for 6,7
A2: 6,7 => SOLVED
* 814293567765184392329657184581462973932571846647839251173948625458326719296715438
A2: 3,8 => CTR
* ...29.567.75..4.92629.57.84.8...29.39325.1.4656743982171.94.23545..2...9.9.7154.8
* PAIR A3: 3,6 BLK 1
A2: 3,6,7,8                              # reduction candidate for 3,6
A2: 3,6 => CTR
* ...29.567.75..4.92.29.57.84.8...29.39325.1.46.6743982171.94.23545..2...9.9.7154.8
A2: 7,8                                  # 22 pairs
* PAIR A3: 3,6 ROW 3
D3: 3,6,1                                # reduction candidate for 3,6
D3: 1 => CTR
* .4.29.567.75..419262915738418467295393258174656743982171.94.2.545..2.679296715438
D3: 3,6                                  # 21 pairs
* PAIR A3: 3,6 COL A
A9: 3,6,2                                # reduction candidate for 3,6
A9: 3,6 => CTR
* .1429.567765..4.92329657184186..29.39325.1.46..7..9..127.94.6.545..267.9.9.715428
A9: 2                                    # 22 pairs
* PAIR F1: 3,8 BLK 2
D2: 3,8,1,6                              # reduction candidate for 3,8
D2: 3,8 => CTR
* .4.29.567.75.6419262915738418467295393258174656743982171.94.2.545..2.679296715438
D2: 1,6                                  # 22 pairs
E2: 3,8,6                                # reduction candidate for 3,8
E2: 3,8 => SOLVED
* 814293567765184392329657184581462973932571846647839251173948625458326719296715438
E2: 6 => CTR
* .4.29.567.75.64.92629.57.8418467295393258174656743982171.94.2.545..2.679296715438
* PAIR F1: 3,8 ROW 1
A1: 3,8,1                                # reduction candidate for 3,8
A1: 3,8                                  # 24 pairs
C1: 3,8,1,4                              # reduction candidate for 3,8
C1: 3,8 => CTR
* .4.29.567..5..4.92.29.57.84.84672953932581746567439821.1.94.2.545..2...9.9.7154.8
C1: 1,4                                  # 24 pairs
* PAIR F1: 3,8 COL F
F7: 3,8,6                                # reduction candidate for 3,8
F7: 3,8 => SOLVED
* 814293567765184392329657184581462973932571846647839251173948625458326719296715438
F7: 6 => CTR
* .1429.567..5..4.92.29.57.84.8..729539325817465.7..9821...946215451.2.679296715438
F8: 3,8,6                                # reduction candidate for 3,8
F8: 3,8 => CTR
* .1429.567..5..4.92.29.57.84.8..729539325817465.7..9821...946215451.2.679296715438
F8: 6 => SOLVED
* 814293567765184392329657184581462973932571846647839251173948625458326719296715438
* PAIR G2: 1,3 ROW 2
D2: 1,3,6,8                              # reduction candidate for 1,3
D2: 6,8 => CTR
* .4.29356737586419262915738418467295393258174656743982171.94.2.545.32.679296715438
D2: 1,3                                  # 23 pairs
* PAIR G3: 1,3 ROW 3
D3: 1,3,6                                # reduction candidate for 1,3
D3: 1,3 => CTR
* .4.29.567.75..4.92629.57.8418467295393258174656743982171.94.2.545..2.679296715438
D3: 6 => SOLVED
* 814293567765184392329657184581462973932571846647839251173948625458326719296715438
* PAIR A6: 5,6 BLK 4
A4: 5,6,1                                # reduction candidate for 5,6
A4: 5,6 => SOLVED
* 814293567765184392329657184581462973932571846647839251173948625458326719296715438
A4: 1 => CTR
* ...29.567..5..4.92.29.57.84184672953932581746567439821...946215451.2.679296715438
* PAIR B6: 4,6 BLK 4
C4: 4,6,1                                # reduction candidate for 4,6
C4: 4,6 => CTR
* ...29.567..5..4.92.29.57.84184672953932581746567439821...946215451.2.679296715438
C4: 1 => SOLVED
* 814293567765184392329657184581462973932571846647839251173948625458326719296715438
* PAIR B6: 4,6 ROW 6
D6: 4,6,3,8                              # reduction candidate for 4,6
D6: 4,6 => CTR
* .1429.567..5..4.92.29.57.84.8..729539325817465.7.39821...946215451.2.679296715438
D6: 3,8 => SOLVED
* 814293567765184392329657184581462973932571846647839251173948625458326719296715438
* PAIR D4: 4,6 BLK 5
D6: 4,6,3,8                              # reduction candidate for 4,6
D6: 4,6 => CTR
* .1429.567..5..4.92.29.57.84.8..729539325817465.7.39821...946215451.2.679296715438
D6: 3,8 => SOLVED
* 814293567765184392329657184581462973932571846647839251173948625458326719296715438
* PAIR D4: 4,6 ROW 4
C4: 4,6,1                                # reduction candidate for 4,6
C4: 4,6 => CTR
* ...29.567..5..4.92.29.57.84184672953932581746567439821...946215451.2.679296715438
C4: 1 => SOLVED
* 814293567765184392329657184581462973932571846647839251173948625458326719296715438
* PAIR B7: 1,7 BLK 7
A7: 1,7,2,3,8                            # reduction candidate for 1,7
A7: 1,7 => SOLVED
* 814293567765184392329657184581462973932571846647839251173948625458326719296715438
A7: 2,3,8 => CTR
* .142935677651843923296571841864729.39325.1.46.47..9..1.7.94...545..2...9.9.7154.8
* PAIR C9: 3,6 BLK 7
A9: 3,6,2                                # reduction candidate for 3,6
A9: 3,6 => CTR
* .1429.567765..4.92329657184186..29.39325.1.46..7..9..127.94.6.545..267.9.9.715428
A9: 2                                    # 22 pairs
* PAIR D8: 3,8 BLK 8
F7: 3,8,6                                # reduction candidate for 3,8
F7: 3,8 => SOLVED
* 814293567765184392329657184581462973932571846647839251173948625458326719296715438
F7: 6 => CTR
* .1429.567..5..4.92.29.57.84.8..729539325817465.7..9821...946215451.2.679296715438
F8: 3,8,6                                # reduction candidate for 3,8
F8: 3,8 => CTR
* .1429.567..5..4.92.29.57.84.8..729539325817465.7..9821...946215451.2.679296715438
F8: 6 => SOLVED
* 814293567765184392329657184581462973932571846647839251173948625458326719296715438
* PAIR D8: 3,8 ROW 8
C8: 3,8,1                                # reduction candidate for 3,8
C8: 3,8 => SOLVED
* 814293567765184392329657184581462973932571846647839251173948625458326719296715438
C8: 1 => CTR
* .1429.567..5..4.92.29.57.84186472953932581746547..9821.7.94...5451.2...9.9.7154.8
* PAIR D8: 3,8 COL D
D2: 3,8,1,6                              # reduction candidate for 3,8
D2: 3,8 => CTR
* .4.29.567.75.6419262915738418467295393258174656743982171.94.2.545..2.679296715438
D2: 1,6                                  # 22 pairs
D6: 3,8,4,6                              # reduction candidate for 3,8
D6: 3,8 => SOLVED
* 814293567765184392329657184581462973932571846647839251173948625458326719296715438
D6: 4,6 => CTR
* .1429.567..5..4.92.29.57.84.8..729539325817465.7.39821...946215451.2.679296715438
* PAIR H9: 2,3 BLK 9
H7: 2,3,1                                # reduction candidate for 2,3
H7: 2,3 => SOLVED
* 814293567765184392329657184581462973932571846647839251173948625458326719296715438
H7: 1 => CTR
* .1429.567..5..4.92.29.57.84186472953932581746547..9821.7.94..15451.2...9.9.7154.8
* PAIR H9: 2,3 ROW 9
A9: 2,3,6                                # reduction candidate for 2,3
A9: 6 => CTR
* ...29.567..5..4.92.29.57.84.8...29.39325.1.46..7..9..127.94.6.545..267.9693715428
A9: 2,3                                  # 22 pairs
* INCONCLUSIVE
* SAVE PR GRAPH zz-www.sudokuoftheday.co.uk-20190129-absurd-base-pr-000.dot
* REASONING
* DIS # C1: 3,8 => CTR => C1: 1,4
* PRF # A2: 6,7 => SOL
* DIS # A2: 3,8 => CTR => A2: 6,7
* DIS # A2: 3,6 => CTR => A2: 7,8
* DIS # D3: 1 => CTR => D3: 3,6
* DIS # A9: 3,6 => CTR => A9: 2
* DIS # D2: 3,8 => CTR => D2: 1,6
* PRF # E2: 3,8 => SOL
* DIS # E2: 6 => CTR => E2: 3,8
* DIS # C1: 3,8 => CTR => C1: 1,4
* PRF # F7: 3,8 => SOL
* DIS # F7: 6 => CTR => F7: 3,8
* DIS # F8: 3,8 => CTR => F8: 6
* PRF # F8: 6 => SOL
* DIS # D2: 6,8 => CTR => D2: 1,3
* DIS # D3: 1,3 => CTR => D3: 6
* PRF # D3: 6 => SOL
* PRF # A4: 5,6 => SOL
* DIS # A4: 1 => CTR => A4: 5,6
* DIS # C4: 4,6 => CTR => C4: 1
* PRF # C4: 1 => SOL
* DIS # D6: 4,6 => CTR => D6: 3,8
* PRF # D6: 3,8 => SOL
* DIS # D6: 4,6 => CTR => D6: 3,8
* PRF # D6: 3,8 => SOL
* DIS # C4: 4,6 => CTR => C4: 1
* PRF # C4: 1 => SOL
* PRF # A7: 1,7 => SOL
* DIS # A7: 2,3,8 => CTR => A7: 1,7
* DIS # A9: 3,6 => CTR => A9: 2
* PRF # F7: 3,8 => SOL
* DIS # F7: 6 => CTR => F7: 3,8
* DIS # F8: 3,8 => CTR => F8: 6
* PRF # F8: 6 => SOL
* PRF # C8: 3,8 => SOL
* DIS # C8: 1 => CTR => C8: 3,8
* DIS # D2: 3,8 => CTR => D2: 1,6
* PRF # D6: 3,8 => SOL
* DIS # D6: 4,6 => CTR => D6: 3,8
* PRF # H7: 2,3 => SOL
* DIS # H7: 1 => CTR => H7: 2,3
* DIS # A9: 6 => CTR => A9: 2,3
* CNT  42 HDP CHAINS /  53 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A3,A6,B1,B2,B6,B7,C9,D4,D8,E4,E5,F1,G2,G3,G5,G6,G7,G8,H4,H6,H9)
* ...29.567..5..4.92.29.57.84.8...29.39325.1.46..7..9..1...94...545..2...9.9.7154.8
* PAIR B1: 1,4 BLK 1
C1: 1,4,3,8                              # reduction candidate for 1,4
C1: 3,8 => CTR
* .4.29.567..5..4.92.29.57.84.84672953932581746567439821.1.94.2.545..2...9.9.7154.8
* PAIR B2: 6,7 BLK 1
A2: 6,7,3,8                              # reduction candidate for 6,7
A2: 6,7 => SOLVED
* 814293567765184392329657184581462973932571846647839251173948625458326719296715438
* DURATION: 0:00:03.351359  START: 03:19:32.340466  END: 03:19:35.691825 2019-05-01
* SOLUTION FOUND
* SAVE PR GRAPH zz-www.sudokuoftheday.co.uk-20190129-absurd-base-pr-001.dot
* REASONING
* DIS # C1: 3,8 => CTR => C1: 1,4
* PRF C1: 1,4 # A2: 6,7 => SOL
* STA C1: 1,4 + A2: 6,7
* CNT   2 HDP CHAINS /   3 HYP OPENED

Header Info

http://www.sudokuoftheday.co.uk/cgi-bin/sudoku1280.cgi?ACTION=archive2&USER=&MONTH=Jan&YEAR=2019, 20190129, absurd

Solution

position: 814293567765184392329657184581462973932571846647839251173948625458326719296715438 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:

* INC # C1: 1,4 => UNS
* DIS # C1: 3,8 => CTR => C1: 1,4
* PRF # A2: 6,7 => SOL
* DIS # A2: 3,8 => CTR => A2: 6,7
* DIS # A2: 3,6 => CTR => A2: 7,8
* INC # A2: 7,8 => UNS
* INC # D3: 3,6 => UNS
* DIS # D3: 1 => CTR => D3: 3,6
* DIS # A9: 3,6 => CTR => A9: 2
* INC # A9: 2 => UNS
* DIS # D2: 3,8 => CTR => D2: 1,6
* INC # D2: 1,6 => UNS
* PRF # E2: 3,8 => SOL
* DIS # E2: 6 => CTR => E2: 3,8
* INC # A1: 3,8 => UNS
* DIS # C1: 3,8 => CTR => C1: 1,4
* INC # C1: 1,4 => UNS
* PRF # F7: 3,8 => SOL
* DIS # F7: 6 => CTR => F7: 3,8
* DIS # F8: 3,8 => CTR => F8: 6
* PRF # F8: 6 => SOL
* INC # D2: 1,3 => UNS
* DIS # D2: 6,8 => CTR => D2: 1,3
* DIS # D3: 1,3 => CTR => D3: 6
* PRF # D3: 6 => SOL
* PRF # A4: 5,6 => SOL
* DIS # A4: 1 => CTR => A4: 5,6
* DIS # C4: 4,6 => CTR => C4: 1
* PRF # C4: 1 => SOL
* DIS # D6: 4,6 => CTR => D6: 3,8
* PRF # D6: 3,8 => SOL
* DIS # D6: 4,6 => CTR => D6: 3,8
* PRF # D6: 3,8 => SOL
* DIS # C4: 4,6 => CTR => C4: 1
* PRF # C4: 1 => SOL
* PRF # A7: 1,7 => SOL
* DIS # A7: 2,3,8 => CTR => A7: 1,7
* DIS # A9: 3,6 => CTR => A9: 2
* INC # A9: 2 => UNS
* PRF # F7: 3,8 => SOL
* DIS # F7: 6 => CTR => F7: 3,8
* DIS # F8: 3,8 => CTR => F8: 6
* PRF # F8: 6 => SOL
* PRF # C8: 3,8 => SOL
* DIS # C8: 1 => CTR => C8: 3,8
* DIS # D2: 3,8 => CTR => D2: 1,6
* INC # D2: 1,6 => UNS
* PRF # D6: 3,8 => SOL
* DIS # D6: 4,6 => CTR => D6: 3,8
* PRF # H7: 2,3 => SOL
* DIS # H7: 1 => CTR => H7: 2,3
* INC # A9: 2,3 => UNS
* DIS # A9: 6 => CTR => A9: 2,3
* CNT  53 HDP CHAINS /  53 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # C1: 1,4 => UNS
* DIS # C1: 3,8 => CTR => C1: 1,4
* PRF C1: 1,4 # A2: 6,7 => SOL
* STA C1: 1,4 + A2: 6,7
* CNT   3 HDP CHAINS /   3 HYP OPENED