# Sudoku from http://www.sudokuwiki.org/Print_Weekly_Sudoku.asp?unsolvable=338

level: deep

position: .......69..6..7..8.1....4....8..6..76......5..2..4....5....9.81...1..3...3..2.... initial

# Autosolve

position: .......69..6..7..8.1....4....8..6..76......5..2..4....5....9.81...1..3...3..2.... autosolve

# Pair Reduction Variants

## Deep Pair Reduction

Time used: 0:00:00.127524

## Deep Constraint Pair Analysis

Time used: 0:00:00.000011

List of important HDP chains detected for C7,G7: 2..:

```* PRF # G7: 2 # G1: 1,5 => SOL
* STA # G7: 2 + G1: 1,5
* CNT   1 HDP CHAINS /   2 HYP OPENED
```

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

# Details

This sudoku is deep. Here is some information that may be helpful on how to proceed.

## Positions

 .......69..6..7..8.1....4....8..6..76......5..2..4....5....9.81...1..3...3..2.... initial .......69..6..7..8.1....4....8..6..76......5..2..4....5....9.81...1..3...3..2.... autosolve

level: deep

## Pairing Analysis

```--------------------------------------------------
* PAIRS (1)
I6: 3,6

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
A9,C9: 1.. / A9 = 1  =>  2 pairs (_) / C9 = 1  =>  1 pairs (_)
C7,G7: 2.. / C7 = 2  =>  2 pairs (_) / G7 = 2  =>  6 pairs (_)
D7,E7: 3.. / D7 = 3  =>  2 pairs (_) / E7 = 3  =>  1 pairs (_)
H4,I5: 4.. / H4 = 4  =>  4 pairs (_) / I5 = 4  =>  3 pairs (_)
B4,C6: 5.. / B4 = 5  =>  2 pairs (_) / C6 = 5  =>  2 pairs (_)
D3,E3: 6.. / D3 = 6  =>  2 pairs (_) / E3 = 6  =>  2 pairs (_)
G6,I6: 6.. / G6 = 6  =>  4 pairs (_) / I6 = 6  =>  1 pairs (_)
B7,B8: 6.. / B7 = 6  =>  3 pairs (_) / B8 = 6  =>  2 pairs (_)
G1,H3: 7.. / G1 = 7  =>  3 pairs (_) / H3 = 7  =>  2 pairs (_)
G5,G6: 8.. / G5 = 8  =>  1 pairs (_) / G6 = 8  =>  1 pairs (_)
B1,B8: 8.. / B1 = 8  =>  1 pairs (_) / B8 = 8  =>  4 pairs (_)
* DURATION: 0:00:06.218390  START: 18:56:18.740638  END: 18:56:24.959028 2019-04-28
* CP COUNT: (11)
* INCONCLUSIVE

--------------------------------------------------
* DEEP CONSTRAINT PAIRS (PAIR REDUCTION)
C7,G7: 2.. / C7 = 2  =>  0 pairs (X) / G7 = 2 ==>  0 pairs (*)
* DURATION: 0:00:08.710264  START: 18:56:25.537869  END: 18:56:34.248133 2019-04-28
* REASONING C7,G7: 2..
* PRF # G7: 2 # G1: 1,5 => SOL
* STA # G7: 2 + G1: 1,5
* CNT   1 HDP CHAINS /   2 HYP OPENED
* DCP COUNT: (1)
* SOLUTION FOUND
```

```http://www.sudokuwiki.org/Print_Weekly_Sudoku.asp?unsolvable=338
```

# Appendix: Full HDP Chains

## A1. Deep Constraint Pair Analysis

Full list of HDP chains traversed for C7,G7: 2..:

```* PRF # G7: 2 # G1: 1,5 => SOL
* STA # G7: 2 + G1: 1,5
* CNT   1 HDP CHAINS /   2 HYP OPENED
```