Minimalist solution to Kirkman's schoolgirl problem ——by Liang Haisheng 2019《Pithy Formula 124 》

Minimalist solution to Kirkman's schoolgirl problem
——by Liang Haisheng 2019

《Pithy Formula 124 》

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1 2 4, 2 3 5, 3 4 6, 4 5 7, 5 6 1, 6 7 2, 7 1 3
2 3 5, 3 4 6, 4 5 7, 5 6 1, 6 7 2, 7 1 3, 1 2 4
3 4 6, 4 5 7, 5 6 1, 6 7 2, 7 1 3, 1 2 4, 2 3 5
4 5 7, 5 6 1, 6 7 2, 7 1 3, 1 2 4, 2 3 5, 3 4 6 :4
5 6 1, 6 7 2, 7 1 3, 1 2 4, 2 3 5, 3 4 6, 4 5 7
6 7 2, 7 1 3, 1 2 4, 2 3 5, 3 4 6, 4 5 7,5 6 1 :2
7 1 3, 1 2 4, 2 3 5, 3 4 6, 4 5 7, 5 6 1, 6 7 2 :1

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1 2 4. OOO
2’ 3’ 5 = XXO
3 4’ 6‘ OXX
5’ 6 1’ XOX
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124, 235, 346, 457, 561, 672, 713
2’3’5, 3’4’6, 4’5’7, 5’6’1, 6’7’2, 7’1’3, 1’2’ 4
34’6’, 45’7’, 56’1’, 67’2’, 71’3’, 12’4’, 23’5’
5’61’, 6’72’, 7’13’, 1’24’, 2’35’, 3’46’, 4’57’

77’0, 11’0, 22’0, 33’0, 44’0, 55’0, 66’0
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1’=8, 2’=9, 3’=A, 4’=B, 5’=C, 6’=D, 7’=E, 0=F

124 235 346 457 561 672 713
9A5 AB6 BC7 CD1 DE2 E83 894
3BD 4CE 5D8 6E9 78A 19B 2AC
C68 D79 E1A 82B 93C A4D B5E
7EF 18F 29F 3AF 4BF 5CF 6DF