let C be Simple_closed_curve; for i, j, k, n being Nat st n is_sufficiently_large_for C & 1 <= k & k <= len (Span (C,n)) & [i,j] in Indices (Gauge (C,n)) & (Span (C,n)) /. k = (Gauge (C,n)) * (i,j) holds
i < len (Gauge (C,n))
let i, j, k, n be Nat; ( n is_sufficiently_large_for C & 1 <= k & k <= len (Span (C,n)) & [i,j] in Indices (Gauge (C,n)) & (Span (C,n)) /. k = (Gauge (C,n)) * (i,j) implies i < len (Gauge (C,n)) )
assume that
A1:
n is_sufficiently_large_for C
and
A2:
1 <= k
and
A3:
k <= len (Span (C,n))
and
A4:
[i,j] in Indices (Gauge (C,n))
and
A5:
(Span (C,n)) /. k = (Gauge (C,n)) * (i,j)
; i < len (Gauge (C,n))
A6:
len (Span (C,n)) > 4
by GOBOARD7:34;
SpanStart (C,n) in BDD C
by A1, Th6;
then A7:
E-bound C >= E-bound (BDD C)
by JORDAN1C:7;
A8:
1 <= j
by A4, MATRIX_0:32;
k in dom (Span (C,n))
by A2, A3, FINSEQ_3:25;
then
(Span (C,n)) /. k in L~ (Span (C,n))
by A6, GOBOARD1:1, XXREAL_0:2;
then A9:
E-bound (L~ (Span (C,n))) >= ((Gauge (C,n)) * (i,j)) `1
by A5, PSCOMP_1:24;
A10:
BDD C c= Cl (BDD C)
by PRE_TOPC:18;
A11:
BDD C is bounded
by JORDAN2C:106;
then A12:
Cl (BDD C) is compact
by TOPREAL6:79;
SpanStart (C,n) in BDD C
by A1, Th6;
then A13:
E-bound (BDD C) = E-bound (Cl (BDD C))
by A11, TOPREAL6:86;
L~ (Span (C,n)) c= BDD C
by A1, Th21;
then
E-bound (L~ (Span (C,n))) <= E-bound (Cl (BDD C))
by A12, A10, PSCOMP_1:67, XBOOLE_1:1;
then A14:
E-bound (BDD C) >= ((Gauge (C,n)) * (i,j)) `1
by A13, A9, XXREAL_0:2;
A15:
len (Gauge (C,n)) >= 4
by JORDAN8:10;
then
len (Gauge (C,n)) >= 1 + 1
by XXREAL_0:2;
then A16:
(len (Gauge (C,n))) - 1 >= 1
by XREAL_1:19;
A17:
(len (Gauge (C,n))) -' 1 >= 1
by A16, XREAL_0:def 2;
A18:
j <= width (Gauge (C,n))
by A4, MATRIX_0:32;
len (Gauge (C,n)) = width (Gauge (C,n))
by JORDAN8:def 1;
then
((Gauge (C,n)) * (((len (Gauge (C,n))) -' 1),j)) `1 = E-bound C
by A8, A18, JORDAN8:12;
then A19:
((Gauge (C,n)) * (((len (Gauge (C,n))) -' 1),j)) `1 >= ((Gauge (C,n)) * (i,j)) `1
by A7, A14, XXREAL_0:2;
i <= len (Gauge (C,n))
by A4, MATRIX_0:32;
then
i <= (len (Gauge (C,n))) -' 1
by A8, A18, A17, A19, GOBOARD5:3;
then
i < ((len (Gauge (C,n))) -' 1) + 1
by NAT_1:13;
hence
i < len (Gauge (C,n))
by A15, XREAL_1:235, XXREAL_0:2; verum