let C be connected compact non horizontal non vertical Subset of (TOP-REAL 2); for n being Element of NAT st n > 0 holds
for i, j being Element of NAT st 1 <= i & i <= len (Gauge C,n) & 1 <= j & j <= width (Gauge C,n) & (Gauge C,n) * i,j in L~ (Cage C,n) holds
LSeg ((Gauge C,n) * i,1),((Gauge C,n) * i,j) meets Lower_Arc (L~ (Cage C,n))
let n be Element of NAT ; ( n > 0 implies for i, j being Element of NAT st 1 <= i & i <= len (Gauge C,n) & 1 <= j & j <= width (Gauge C,n) & (Gauge C,n) * i,j in L~ (Cage C,n) holds
LSeg ((Gauge C,n) * i,1),((Gauge C,n) * i,j) meets Lower_Arc (L~ (Cage C,n)) )
assume
n > 0
; for i, j being Element of NAT st 1 <= i & i <= len (Gauge C,n) & 1 <= j & j <= width (Gauge C,n) & (Gauge C,n) * i,j in L~ (Cage C,n) holds
LSeg ((Gauge C,n) * i,1),((Gauge C,n) * i,j) meets Lower_Arc (L~ (Cage C,n))
then A1:
L~ (Lower_Seq C,n) = Lower_Arc (L~ (Cage C,n))
by Th64;
let i, j be Element of NAT ; ( 1 <= i & i <= len (Gauge C,n) & 1 <= j & j <= width (Gauge C,n) & (Gauge C,n) * i,j in L~ (Cage C,n) implies LSeg ((Gauge C,n) * i,1),((Gauge C,n) * i,j) meets Lower_Arc (L~ (Cage C,n)) )
assume
( 1 <= i & i <= len (Gauge C,n) & 1 <= j & j <= width (Gauge C,n) & (Gauge C,n) * i,j in L~ (Cage C,n) )
; LSeg ((Gauge C,n) * i,1),((Gauge C,n) * i,j) meets Lower_Arc (L~ (Cage C,n))
hence
LSeg ((Gauge C,n) * i,1),((Gauge C,n) * i,j) meets Lower_Arc (L~ (Cage C,n))
by A1, Th54; verum