... by: Norman Powell
Forcing Networks nibble away at the possibilities until eventual returning a solution (your Bowman's Bingo)See steps below (reverse order):
Forcing Networks Solution Found - Eliminate all Trial OFFs
Forcing Networks Possibilities Forced to Same State when Value 3 in Cell E8 is ON or OFF
Eliminate Forced OFF Possibility: Value 6 in Cell F7
Forcing Networks Value 3 in Row 8 Column F cannot be ON so eliminate
Contradiction: More than one Value 4 ON in Column A
Forcing Networks Value 4 in Row 8 Column E cannot be ON so eliminate
Contradiction: No possibilities left for Row 8 Column B
Forcing Networks Value 4 in Row 9 Column C cannot be ON so eliminate
Contradiction: More than one Value ON in Row 4 Column F
Forcing Networks Value 1 in Row 9 Column C cannot be ON so eliminate
Contradiction: No possibilities left for Row 8 Column I
Confined to Box Value 2 is confined to Column D and Box 2.
Forcing Networks Value 2 in Row 8 Column D cannot be ON so eliminate
Contradiction: No possibilities left for Value 5 in Row 7
Confined to Box Value 7 is confined to Row 2 and Box 3.
Forcing Networks Value 7 in Row 3 Column G cannot be ON so eliminate
Contradiction: No possibilities left for Row 7 Column D
Forcing Networks Value 6 in Row 3 Column B cannot be ON so eliminate
Contradiction: No possibilities left for Row 3 Column G
Forcing Networks Value 1 in Row 6 Column B cannot be ON so eliminate
Contradiction: More than one Value 8 ON in Row 7
Forcing Networks Value 6 in Row 3 Column F cannot be ON so eliminate
Contradiction: No possibilities left for Row 7 Column B
Forcing Networks Value 2 in Row 7 Column F cannot be ON so eliminate
Contradiction: More than one Value 8 ON in Box 5
Forcing Networks Value 2 in Row 7 Column D cannot be ON so eliminate
Contradiction: More than one Value ON in Row 3 Column B
Forcing Networks Value 2 in Row 8 Column G cannot be ON so eliminate
Contradiction: More than one Value ON in Row 7 Column C
Forcing Networks Value 2 in Row 3 Column I cannot be ON so eliminate
Contradiction: No possibilities left for Value 4 in Row 4
Forcing Networks Value 7 in Row 2 Column C cannot be ON so eliminate
Contradiction: No possibilities left for Row 9 Column G
Forcing Networks Value 1 in Row 6 Column C cannot be ON so eliminate
Contradiction: More than one Value 6 ON in Row 9
Forcing Networks Value 1 in Row 4 Column I cannot be ON so eliminate
Contradiction: No possibilities left for Row 3 Column F
Forcing Networks Value 2 in Row 7 Column G cannot be ON so eliminate
Contradiction: More than one Value ON in Row 8 Column F
Confined to Box Value 5 is confined to Column G and Box 9.
Forcing Networks Value 5 in Row 7 Column H cannot be ON so eliminate
Contradiction: No possibilities left for Value 7 in Row 6
Forcing Networks Value 7 in Row 1 Column H cannot be ON so eliminate
Contradiction: More than one Value ON in Row 3 Column I
Forcing Networks Value 7 in Row 2 Column F cannot be ON so eliminate
Contradiction: More than one Value ON in Row 5 Column G
Forcing Networks Value 9 in Row 2 Column C cannot be ON so eliminate
Contradiction: No possibilities left for Value 4 in Row 9
Forcing Networks Value 1 in Row 4 Column G cannot be ON so eliminate
Contradiction: No possibilities left for Row 9 Column H
Forcing Networks Value 6 in Row 1 Column D cannot be ON so eliminate
Contradiction: More than one Value 4 ON in Row 8
Forcing Networks Value 7 in Row 7 Column D cannot be ON so eliminate
Contradiction: No possibilities left for Value 2 in Column C
Forcing Networks Value 2 in Row 8 Column I cannot be ON so eliminate
Contradiction: More than one Value ON in Row 1 Column H
Hidden Pairs Hidden Pair in Row 6, for Values: 3 5 in Cells: E6 H6