theorem Th23:
for
n being
Nat for
C being
Simple_closed_curve for
i,
j,
k being
Nat st 1
< i &
i < len (Gauge (C,n)) & 1
<= j &
j <= k &
k <= width (Gauge (C,n)) &
n > 0 &
(Gauge (C,n)) * (
i,
k)
in Upper_Arc (L~ (Cage (C,n))) &
(Gauge (C,n)) * (
i,
j)
in Lower_Arc (L~ (Cage (C,n))) holds
LSeg (
((Gauge (C,n)) * (i,j)),
((Gauge (C,n)) * (i,k)))
meets Lower_Arc C