The graph of the Seven Bridges of Konigsberg and its dual graph
(E53 p.128=2^7, 7=6+1=3+1+3)
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*E*E*
EEEE
*E*
V=5 (the number of left errors)
E=7 (128=2^7)
F=4 (the number of left 1s)
V-E+F=2 (the number of right errors)
05=Co 11=Figura
the number of errors=7 bridges
the number of - or 1=6 bridges
variant and invariant
(2005, Nov. 16-2007, May 10, August 25)