let C be connected compact non horizontal non vertical Subset of (TOP-REAL 2); :: thesis: 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 < width (Gauge C,n)
let i, n, j be Element of NAT ; :: thesis: ( i <= len (Gauge C,n) & j <= width (Gauge C,n) & cell (Gauge C,n),i,j c= BDD C implies j + 1 < width (Gauge C,n) )
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
; :: thesis: j + 1 < width (Gauge C,n)
assume
j + 1 >= width (Gauge C,n)
; :: thesis: contradiction
then A4:
( j + 1 > width (Gauge C,n) or j + 1 = width (Gauge C,n) )
by XXREAL_0:1;
A5:
( j < width (Gauge C,n) or j = width (Gauge C,n) )
by A2, XXREAL_0:1;
per cases
( j = width (Gauge C,n) or j + 1 = width (Gauge C,n) )
by A4, A5, NAT_1:13;
suppose
j + 1
= width (Gauge C,n)
;
:: thesis: contradictionthen A6:
cell (Gauge C,n),
i,
((width (Gauge C,n)) -' 1) c= BDD C
by A3, NAT_D:34;
(width (Gauge C,n)) -' 1
<= width (Gauge C,n)
by NAT_D:44;
then A7:
not
cell (Gauge C,n),
i,
((width (Gauge C,n)) -' 1) is
empty
by A1, JORDAN1A:45;
A8:
cell (Gauge C,n),
i,
(width (Gauge C,n)) c= UBD C
by A1, JORDAN1A:71;
A9:
width (Gauge C,n) <> 0
by GOBOARD1:def 5;
A10:
i < len (Gauge C,n)
by A1, A2, A3, Lm5, XXREAL_0:1;
A11:
(width (Gauge C,n)) - 1
< width (Gauge C,n)
by XREAL_1:148;
then A12:
(width (Gauge C,n)) -' 1
< width (Gauge C,n)
by A9, XREAL_1:235, NAT_1:14;
A13:
((width (Gauge C,n)) -' 1) + 1
= width (Gauge C,n)
by A9, XREAL_1:237, NAT_1:14;
i <> 0
by A2, A3, Lm3;
then
(cell (Gauge C,n),i,(width (Gauge C,n))) /\ (cell (Gauge C,n),i,((width (Gauge C,n)) -' 1)) = LSeg ((Gauge C,n) * i,(width (Gauge C,n))),
((Gauge C,n) * (i + 1),(width (Gauge C,n)))
by A10, A11, A13, GOBOARD5:27, NAT_1:14;
then A14:
cell (Gauge C,n),
i,
(width (Gauge C,n)) meets cell (Gauge C,n),
i,
((width (Gauge C,n)) -' 1)
by XBOOLE_0:def 7;
UBD C is_outside_component_of C
by JORDAN2C:73, JORDAN2C:76;
then A15:
UBD C is_a_component_of C `
by JORDAN2C:def 4;
BDD C c= C `
by JORDAN2C:29;
then
cell (Gauge C,n),
i,
((width (Gauge C,n)) -' 1) c= C `
by A6, XBOOLE_1:1;
then
cell (Gauge C,n),
i,
((width (Gauge C,n)) -' 1) c= UBD C
by A1, A8, A12, A14, A15, GOBOARD9:6, JORDAN1A:46;
hence
contradiction
by A6, A7, JORDAN2C:28, XBOOLE_1:68;
:: thesis: verum end; end;