let C be Simple_closed_curve; :: thesis: for i, j, k, n being Element of 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 Element of NAT ; :: thesis: ( 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 & k <= len (Span C,n) )
and
A3:
[i,j] in Indices (Gauge C,n)
and
A4:
(Span C,n) /. k = (Gauge C,n) * i,j
; :: thesis: i < len (Gauge C,n)
A5:
( 1 <= i & i <= len (Gauge C,n) & 1 <= j & j <= width (Gauge C,n) )
by A3, MATRIX_1:39;
len (Gauge C,n) = width (Gauge C,n)
by JORDAN8:def 1;
then A6:
((Gauge C,n) * ((len (Gauge C,n)) -' 1),j) `1 = E-bound C
by A5, JORDAN8:15;
SpanStart C,n in BDD C
by A1, Th7;
then A7:
E-bound C >= E-bound (BDD C)
by JORDAN1C:19;
A8:
BDD C is Bounded
by JORDAN2C:114;
then A9:
Cl (BDD C) is compact
by TOPREAL6:71, TOPREAL6:88;
A10:
BDD C c= Cl (BDD C)
by PRE_TOPC:48;
L~ (Span C,n) c= BDD C
by A1, Th22;
then A11:
E-bound (L~ (Span C,n)) <= E-bound (Cl (BDD C))
by A9, A10, PSCOMP_1:130, XBOOLE_1:1;
SpanStart C,n in BDD C
by A1, Th7;
then A12:
E-bound (BDD C) = E-bound (Cl (BDD C))
by A8, TOPREAL6:95;
A13:
len (Gauge C,n) >= 4
by JORDAN8:13;
then
len (Gauge C,n) >= 0 + 1
by XXREAL_0:2;
then A14:
(len (Gauge C,n)) - 1 >= 0
by XREAL_1:21;
len (Gauge C,n) >= 1 + 1
by A13, XXREAL_0:2;
then
(len (Gauge C,n)) - 1 >= 1
by XREAL_1:21;
then A15:
(len (Gauge C,n)) -' 1 >= 1
by A14, XREAL_0:def 2;
A16:
len (Span C,n) > 4
by GOBOARD7:36;
k in dom (Span C,n)
by A2, FINSEQ_3:27;
then
(Span C,n) /. k in L~ (Span C,n)
by A16, GOBOARD1:16, XXREAL_0:2;
then
E-bound (L~ (Span C,n)) >= ((Gauge C,n) * i,j) `1
by A4, PSCOMP_1:71;
then
E-bound (BDD C) >= ((Gauge C,n) * i,j) `1
by A11, A12, XXREAL_0:2;
then
((Gauge C,n) * ((len (Gauge C,n)) -' 1),j) `1 >= ((Gauge C,n) * i,j) `1
by A6, A7, XXREAL_0:2;
then
i <= (len (Gauge C,n)) -' 1
by A5, A15, GOBOARD5:4;
then
i < ((len (Gauge C,n)) -' 1) + 1
by NAT_1:13;
hence
i < len (Gauge C,n)
by A13, XREAL_1:237, XXREAL_0:2; :: thesis: verum