theorem Th66: :: GLIB_001:68

for G being _Graph
for W being Walk of G
for n being odd Element of NAT st n <= len W holds
( (2 * ((n + 1) div 2)) - 1 = n & 1 <= (n + 1) div 2 & (n + 1) div 2 <= len (W .vertexSeq()) )