let C be connected compact non horizontal non vertical Subset of (TOP-REAL 2); for i, n, j being Element of NAT st i <= len (Gauge C,n) & j <= width (Gauge C,n) & cell (Gauge C,n),i,j c= BDD C holds
j > 1
let i, n, j be Element of NAT ; ( i <= len (Gauge C,n) & j <= width (Gauge C,n) & cell (Gauge C,n),i,j c= BDD C implies j > 1 )
assume that
A1:
i <= len (Gauge C,n)
and
A2:
j <= width (Gauge C,n)
and
A3:
cell (Gauge C,n),i,j c= BDD C
and
A4:
j <= 1
; contradiction
per cases
( j = 0 or j = 1 )
by A4, NAT_1:26;
suppose A5:
j = 1
;
contradiction
BDD C c= C `
by JORDAN2C:29;
then A6:
cell (Gauge C,n),
i,1
c= C `
by A3, A5, XBOOLE_1:1;
A7:
i <> 0
by A2, A3, Lm3;
UBD C is_outside_component_of C
by JORDAN2C:73, JORDAN2C:76;
then A8:
UBD C is_a_component_of C `
by JORDAN2C:def 4;
A9:
width (Gauge C,n) <> 0
by GOBOARD1:def 5;
then A10:
0 + 1
<= width (Gauge C,n)
by NAT_1:14;
then A11:
not
cell (Gauge C,n),
i,1 is
empty
by A1, JORDAN1A:45;
i < len (Gauge C,n)
by A1, A2, A3, Lm5, XXREAL_0:1;
then
(cell (Gauge C,n),i,0 ) /\ (cell (Gauge C,n),i,(0 + 1)) = LSeg ((Gauge C,n) * i,(0 + 1)),
((Gauge C,n) * (i + 1),(0 + 1))
by A9, A7, GOBOARD5:27, NAT_1:14;
then A12:
cell (Gauge C,n),
i,
0 meets cell (Gauge C,n),
i,
(0 + 1)
by XBOOLE_0:def 7;
cell (Gauge C,n),
i,
0 c= UBD C
by A1, JORDAN1A:70;
then
cell (Gauge C,n),
i,1
c= UBD C
by A1, A10, A12, A8, A6, GOBOARD9:6, JORDAN1A:46;
hence
contradiction
by A3, A5, A11, JORDAN2C:28, XBOOLE_1:68;
verum end; end;