let n be Nat; for C being connected compact non horizontal non vertical Subset of (TOP-REAL 2)
for p, x being Point of (TOP-REAL 2) st x in E-most C & p in (east_halfline x) /\ (L~ (Cage (C,n))) holds
p `1 = E-bound (L~ (Cage (C,n)))
let C be connected compact non horizontal non vertical Subset of (TOP-REAL 2); for p, x being Point of (TOP-REAL 2) st x in E-most C & p in (east_halfline x) /\ (L~ (Cage (C,n))) holds
p `1 = E-bound (L~ (Cage (C,n)))
let p, x be Point of (TOP-REAL 2); ( x in E-most C & p in (east_halfline x) /\ (L~ (Cage (C,n))) implies p `1 = E-bound (L~ (Cage (C,n))) )
set G = Gauge (C,n);
set f = Cage (C,n);
A1:
Cage (C,n) is_sequence_on Gauge (C,n)
by JORDAN9:def 1;
assume A2:
x in E-most C
; ( not p in (east_halfline x) /\ (L~ (Cage (C,n))) or p `1 = E-bound (L~ (Cage (C,n))) )
then A3:
x in C
by XBOOLE_0:def 4;
A4:
(len (Gauge (C,n))) -' 1 <= len (Gauge (C,n))
by NAT_D:35;
A5:
len (Gauge (C,n)) = width (Gauge (C,n))
by JORDAN8:def 1;
assume A6:
p in (east_halfline x) /\ (L~ (Cage (C,n)))
; p `1 = E-bound (L~ (Cage (C,n)))
then
p in L~ (Cage (C,n))
by XBOOLE_0:def 4;
then consider i being Nat such that
A7:
1 <= i
and
A8:
i + 1 <= len (Cage (C,n))
and
A9:
p in LSeg ((Cage (C,n)),i)
by SPPOL_2:13;
A10:
LSeg ((Cage (C,n)),i) = LSeg (((Cage (C,n)) /. i),((Cage (C,n)) /. (i + 1)))
by A7, A8, TOPREAL1:def 3;
A11:
i < len (Cage (C,n))
by A8, NAT_1:13;
then
i in Seg (len (Cage (C,n)))
by A7, FINSEQ_1:1;
then
i in dom (Cage (C,n))
by FINSEQ_1:def 3;
then consider i1, i2 being Nat such that
A12:
[i1,i2] in Indices (Gauge (C,n))
and
A13:
(Cage (C,n)) /. i = (Gauge (C,n)) * (i1,i2)
by A1, GOBOARD1:def 9;
A14:
( 1 <= i2 & i2 <= width (Gauge (C,n)) )
by A12, MATRIX_0:32;
p in east_halfline x
by A6, XBOOLE_0:def 4;
then
LSeg ((Cage (C,n)),i) is vertical
by A2, A7, A9, A11, Th79;
then
((Cage (C,n)) /. i) `1 = ((Cage (C,n)) /. (i + 1)) `1
by A10, SPPOL_1:16;
then A15:
p `1 = ((Cage (C,n)) /. i) `1
by A9, A10, GOBOARD7:5;
A16:
i1 <= len (Gauge (C,n))
by A12, MATRIX_0:32;
A17:
1 <= i1
by A12, MATRIX_0:32;
x `1 =
(E-min C) `1
by A2, PSCOMP_1:47
.=
E-bound C
by EUCLID:52
.=
((Gauge (C,n)) * (((len (Gauge (C,n))) -' 1),i2)) `1
by A5, A14, JORDAN8:12
;
then
i1 > (len (Gauge (C,n))) -' 1
by A3, A6, A13, A14, A17, A15, A4, Th75, SPRECT_3:13;
then
i1 >= ((len (Gauge (C,n))) -' 1) + 1
by NAT_1:13;
then
i1 >= len (Gauge (C,n))
by A17, XREAL_1:235, XXREAL_0:2;
then
i1 = len (Gauge (C,n))
by A16, XXREAL_0:1;
then
(Cage (C,n)) /. i in E-most (L~ (Cage (C,n)))
by A7, A11, A13, A14, Th61;
hence
p `1 = E-bound (L~ (Cage (C,n)))
by A15, Th4; verum