let C be being_simple_closed_curve Subset of (TOP-REAL 2); (Y-InitStart C) + 1 < width (Gauge C,(ApproxIndex C))
set m = ApproxIndex C;
A1:
(X-SpanStart C,(ApproxIndex C)) -' 1 <= len (Gauge C,(ApproxIndex C))
by JORDAN1H:59;
assume
(Y-InitStart C) + 1 >= width (Gauge C,(ApproxIndex C))
; contradiction
then A2:
( (Y-InitStart C) + 1 > width (Gauge C,(ApproxIndex C)) or (Y-InitStart C) + 1 = width (Gauge C,(ApproxIndex C)) )
by XXREAL_0:1;
A3:
( Y-InitStart C < width (Gauge C,(ApproxIndex C)) or Y-InitStart C = width (Gauge C,(ApproxIndex C)) )
by Def2;
per cases
( Y-InitStart C = width (Gauge C,(ApproxIndex C)) or (Y-InitStart C) + 1 = width (Gauge C,(ApproxIndex C)) )
by A2, A3, NAT_1:13;
suppose
(Y-InitStart C) + 1
= width (Gauge C,(ApproxIndex C))
;
contradictionthen
Y-InitStart C = (width (Gauge C,(ApproxIndex C))) -' 1
by NAT_D:34;
then A4:
cell (Gauge C,(ApproxIndex C)),
((X-SpanStart C,(ApproxIndex C)) -' 1),
((width (Gauge C,(ApproxIndex C))) -' 1) c= BDD C
by Def2;
BDD C c= C `
by JORDAN2C:29;
then A5:
cell (Gauge C,(ApproxIndex C)),
((X-SpanStart C,(ApproxIndex C)) -' 1),
((width (Gauge C,(ApproxIndex C))) -' 1) c= C `
by A4, XBOOLE_1:1;
A6:
cell (Gauge C,(ApproxIndex C)),
((X-SpanStart C,(ApproxIndex C)) -' 1),
(width (Gauge C,(ApproxIndex C))) c= UBD C
by A1, JORDAN1A:71;
set i1 =
X-SpanStart C,
(ApproxIndex C);
A7:
(X-SpanStart C,(ApproxIndex C)) -' 1
<= X-SpanStart C,
(ApproxIndex C)
by NAT_D:44;
X-SpanStart C,
(ApproxIndex C) < len (Gauge C,(ApproxIndex C))
by JORDAN1H:58;
then A8:
(X-SpanStart C,(ApproxIndex C)) -' 1
< len (Gauge C,(ApproxIndex C))
by A7, XXREAL_0:2;
UBD C is_outside_component_of C
by JORDAN2C:76;
then A9:
UBD C is_a_component_of C `
by JORDAN2C:def 4;
(width (Gauge C,(ApproxIndex C))) -' 1
<= width (Gauge C,(ApproxIndex C))
by NAT_D:44;
then A10:
not
cell (Gauge C,(ApproxIndex C)),
((X-SpanStart C,(ApproxIndex C)) -' 1),
((width (Gauge C,(ApproxIndex C))) -' 1) is
empty
by A1, JORDAN1A:45;
A11:
(width (Gauge C,(ApproxIndex C))) - 1
< width (Gauge C,(ApproxIndex C))
by XREAL_1:148;
A12:
1
<= (X-SpanStart C,(ApproxIndex C)) -' 1
by JORDAN1H:59;
A13:
width (Gauge C,(ApproxIndex C)) <> 0
by GOBOARD1:def 5;
then
((width (Gauge C,(ApproxIndex C))) -' 1) + 1
= width (Gauge C,(ApproxIndex C))
by NAT_1:14, XREAL_1:237;
then
(cell (Gauge C,(ApproxIndex C)),((X-SpanStart C,(ApproxIndex C)) -' 1),(width (Gauge C,(ApproxIndex C)))) /\ (cell (Gauge C,(ApproxIndex C)),((X-SpanStart C,(ApproxIndex C)) -' 1),((width (Gauge C,(ApproxIndex C))) -' 1)) = LSeg ((Gauge C,(ApproxIndex C)) * ((X-SpanStart C,(ApproxIndex C)) -' 1),(width (Gauge C,(ApproxIndex C)))),
((Gauge C,(ApproxIndex C)) * (((X-SpanStart C,(ApproxIndex C)) -' 1) + 1),(width (Gauge C,(ApproxIndex C))))
by A8, A11, A12, GOBOARD5:27;
then A14:
cell (Gauge C,(ApproxIndex C)),
((X-SpanStart C,(ApproxIndex C)) -' 1),
(width (Gauge C,(ApproxIndex C))) meets cell (Gauge C,(ApproxIndex C)),
((X-SpanStart C,(ApproxIndex C)) -' 1),
((width (Gauge C,(ApproxIndex C))) -' 1)
by XBOOLE_0:def 7;
(width (Gauge C,(ApproxIndex C))) -' 1
< width (Gauge C,(ApproxIndex C))
by A13, A11, NAT_1:14, XREAL_1:235;
then
cell (Gauge C,(ApproxIndex C)),
((X-SpanStart C,(ApproxIndex C)) -' 1),
((width (Gauge C,(ApproxIndex C))) -' 1) c= UBD C
by A6, A8, A14, A9, A5, GOBOARD9:6, JORDAN1A:46;
hence
contradiction
by A4, A10, JORDAN2C:28, XBOOLE_1:68;
verum end; end;