let a be non empty positive at_most_one FinSequence of REAL ; for h being non empty FinSequence of NAT * st h = OnlinePackingHistory (a,(NextFit a)) holds
for i, j, k being Nat st 1 <= i & i <= len a & rng (h . i) = Seg k & 2 <= k & 1 <= j & j <= k div 2 holds
(SumBin (a,(h . i),{((2 * j) - 1)})) + (SumBin (a,(h . i),{(2 * j)})) > 1
let h be non empty FinSequence of NAT * ; ( h = OnlinePackingHistory (a,(NextFit a)) implies for i, j, k being Nat st 1 <= i & i <= len a & rng (h . i) = Seg k & 2 <= k & 1 <= j & j <= k div 2 holds
(SumBin (a,(h . i),{((2 * j) - 1)})) + (SumBin (a,(h . i),{(2 * j)})) > 1 )
assume HN00:
h = OnlinePackingHistory (a,(NextFit a))
; for i, j, k being Nat st 1 <= i & i <= len a & rng (h . i) = Seg k & 2 <= k & 1 <= j & j <= k div 2 holds
(SumBin (a,(h . i),{((2 * j) - 1)})) + (SumBin (a,(h . i),{(2 * j)})) > 1
let i, j, k be Nat; ( 1 <= i & i <= len a & rng (h . i) = Seg k & 2 <= k & 1 <= j & j <= k div 2 implies (SumBin (a,(h . i),{((2 * j) - 1)})) + (SumBin (a,(h . i),{(2 * j)})) > 1 )
assume that
L100:
1 <= i
and
L101:
i <= len a
and
L200:
rng (h . i) = Seg k
and
L201:
2 <= k
and
L202:
1 <= j
and
L203:
j <= k div 2
; (SumBin (a,(h . i),{((2 * j) - 1)})) + (SumBin (a,(h . i),{(2 * j)})) > 1
set l = (2 * j) - 1;
L298:
2 * 1 <= 2 * j
by L202, XREAL_1:64;
then L299:
(2 * 1) - 1 <= (2 * j) - 1
by XREAL_1:9;
L320:
k mod 2 >= 0
by INT_1:57;
((k div 2) * 2) + (k mod 2) = k
by INT_1:59;
then L339:
(((k div 2) * 2) + (k mod 2)) - (k mod 2) <= k - 0
by L320, XREAL_1:13;
2 * j <= 2 * (k div 2)
by L203, XREAL_1:64;
then
2 * j <= k
by L339, XXREAL_0:2;
then
2 * j < k + 1
by NAT_1:13;
then L399:
(2 * j) - 1 < (k + 1) - 1
by XREAL_1:14;
reconsider l = (2 * j) - 1 as Nat by L298;
(SumBin (a,(h . i),{l})) + (SumBin (a,(h . i),{(l + 1)})) > 1
by HN00, L100, L101, L200, L201, L299, L399, NF820;
hence
(SumBin (a,(h . i),{((2 * j) - 1)})) + (SumBin (a,(h . i),{(2 * j)})) > 1
; verum