let i be Element of NAT ; for C being connected compact non horizontal non vertical Subset of (TOP-REAL 2) st 1 <= i & i <= len (Gauge C,1) holds
((Gauge C,1) * (Center (Gauge C,1)),i) `1 = ((W-bound C) + (E-bound C)) / 2
let C be connected compact non horizontal non vertical Subset of (TOP-REAL 2); ( 1 <= i & i <= len (Gauge C,1) implies ((Gauge C,1) * (Center (Gauge C,1)),i) `1 = ((W-bound C) + (E-bound C)) / 2 )
set a = N-bound C;
set s = S-bound C;
set w = W-bound C;
set e = E-bound C;
set G = Gauge C,1;
assume
( 1 <= i & i <= len (Gauge C,1) )
; ((Gauge C,1) * (Center (Gauge C,1)),i) `1 = ((W-bound C) + (E-bound C)) / 2
then
[(Center (Gauge C,1)),i] in Indices (Gauge C,1)
by Lm4;
hence ((Gauge C,1) * (Center (Gauge C,1)),i) `1 =
|[((W-bound C) + ((((E-bound C) - (W-bound C)) / (2 |^ 1)) * ((Center (Gauge C,1)) - 2))),((S-bound C) + ((((N-bound C) - (S-bound C)) / (2 |^ 1)) * (i - 2)))]| `1
by JORDAN8:def 1
.=
(W-bound C) + ((((E-bound C) - (W-bound C)) / (2 |^ 1)) * ((Center (Gauge C,1)) - 2))
by EUCLID:56
.=
(W-bound C) + (((E-bound C) - (W-bound C)) / 2)
by Lm6
.=
((W-bound C) + (E-bound C)) / 2
;
verum