let n be Element of NAT ; :: thesis: for C being connected compact non horizontal non vertical Subset of (TOP-REAL 2)
for i, j, k being Element of NAT st 1 <= i & i <= len (Gauge C,n) & 1 <= j & j <= k & k <= width (Gauge C,n) & (Gauge C,n) * i,j in L~ (Lower_Seq C,n) & (Gauge C,n) * i,k in L~ (Upper_Seq C,n) holds
ex j1, k1 being Element of NAT st
( j <= j1 & j1 <= k1 & k1 <= k & (LSeg ((Gauge C,n) * i,j1),((Gauge C,n) * i,k1)) /\ (L~ (Lower_Seq C,n)) = {((Gauge C,n) * i,j1)} & (LSeg ((Gauge C,n) * i,j1),((Gauge C,n) * i,k1)) /\ (L~ (Upper_Seq C,n)) = {((Gauge C,n) * i,k1)} )

let C be connected compact non horizontal non vertical Subset of (TOP-REAL 2); :: thesis: for i, j, k being Element of NAT st 1 <= i & i <= len (Gauge C,n) & 1 <= j & j <= k & k <= width (Gauge C,n) & (Gauge C,n) * i,j in L~ (Lower_Seq C,n) & (Gauge C,n) * i,k in L~ (Upper_Seq C,n) holds
ex j1, k1 being Element of NAT st
( j <= j1 & j1 <= k1 & k1 <= k & (LSeg ((Gauge C,n) * i,j1),((Gauge C,n) * i,k1)) /\ (L~ (Lower_Seq C,n)) = {((Gauge C,n) * i,j1)} & (LSeg ((Gauge C,n) * i,j1),((Gauge C,n) * i,k1)) /\ (L~ (Upper_Seq C,n)) = {((Gauge C,n) * i,k1)} )

let i, j, k be Element of NAT ; :: thesis: ( 1 <= i & i <= len (Gauge C,n) & 1 <= j & j <= k & k <= width (Gauge C,n) & (Gauge C,n) * i,j in L~ (Lower_Seq C,n) & (Gauge C,n) * i,k in L~ (Upper_Seq C,n) implies ex j1, k1 being Element of NAT st
( j <= j1 & j1 <= k1 & k1 <= k & (LSeg ((Gauge C,n) * i,j1),((Gauge C,n) * i,k1)) /\ (L~ (Lower_Seq C,n)) = {((Gauge C,n) * i,j1)} & (LSeg ((Gauge C,n) * i,j1),((Gauge C,n) * i,k1)) /\ (L~ (Upper_Seq C,n)) = {((Gauge C,n) * i,k1)} ) )

assume that
A1: ( 1 <= i & i <= len (Gauge C,n) ) and
A2: ( 1 <= j & j <= k & k <= width (Gauge C,n) ) and
A3: (Gauge C,n) * i,j in L~ (Lower_Seq C,n) and
A4: (Gauge C,n) * i,k in L~ (Upper_Seq C,n) ; :: thesis: ex j1, k1 being Element of NAT st
( j <= j1 & j1 <= k1 & k1 <= k & (LSeg ((Gauge C,n) * i,j1),((Gauge C,n) * i,k1)) /\ (L~ (Lower_Seq C,n)) = {((Gauge C,n) * i,j1)} & (LSeg ((Gauge C,n) * i,j1),((Gauge C,n) * i,k1)) /\ (L~ (Upper_Seq C,n)) = {((Gauge C,n) * i,k1)} )

set G = Gauge C,n;
set s = ((Gauge C,n) * i,1) `1 ;
set f = (Gauge C,n) * i,j;
set e = (Gauge C,n) * i,k;
set w1 = inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n))));
set p = |[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|;
set w2 = sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n))));
set q = |[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]|;
A5: Upper_Seq C,n is_sequence_on Gauge C,n by JORDAN1G:4;
A6: (Gauge C,n) * i,k in LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k) by RLTOPSP1:69;
then A7: LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k) meets L~ (Upper_Seq C,n) by A4, XBOOLE_0:3;
A8: j <= width (Gauge C,n) by A2, XXREAL_0:2;
then A9: [i,j] in Indices (Gauge C,n) by A1, A2, MATRIX_1:37;
A10: k >= 1 by A2, XXREAL_0:2;
then [i,k] in Indices (Gauge C,n) by A1, A2, MATRIX_1:37;
then consider k1 being Element of NAT such that
A11: ( j <= k1 & k1 <= k ) and
A12: ((Gauge C,n) * i,k1) `2 = inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))) by A2, A5, A7, A9, JORDAN1F:1;
A13: ( 1 <= k1 & k1 <= width (Gauge C,n) ) by A2, A11, XXREAL_0:2;
then A14: ((Gauge C,n) * i,k1) `1 = ((Gauge C,n) * i,1) `1 by A1, GOBOARD5:3;
then A15: |[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]| = (Gauge C,n) * i,k1 by A12, EUCLID:57;
A16: Lower_Seq C,n is_sequence_on Gauge C,n by JORDAN1G:5;
A17: (Gauge C,n) * i,j in LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k1) by RLTOPSP1:69;
then A18: LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k1) meets L~ (Lower_Seq C,n) by A3, XBOOLE_0:3;
[i,k1] in Indices (Gauge C,n) by A1, A13, MATRIX_1:37;
then consider j1 being Element of NAT such that
A19: ( j <= j1 & j1 <= k1 ) and
A20: ((Gauge C,n) * i,j1) `2 = sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))) by A9, A11, A15, A16, A18, JORDAN1F:2;
A21: ( 1 <= j1 & j1 <= width (Gauge C,n) ) by A2, A13, A19, XXREAL_0:2;
then A22: ((Gauge C,n) * i,j1) `1 = ((Gauge C,n) * i,1) `1 by A1, GOBOARD5:3;
then A23: |[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]| = (Gauge C,n) * i,j1 by A20, EUCLID:57;
take j1 ; :: thesis: ex k1 being Element of NAT st
( j <= j1 & j1 <= k1 & k1 <= k & (LSeg ((Gauge C,n) * i,j1),((Gauge C,n) * i,k1)) /\ (L~ (Lower_Seq C,n)) = {((Gauge C,n) * i,j1)} & (LSeg ((Gauge C,n) * i,j1),((Gauge C,n) * i,k1)) /\ (L~ (Upper_Seq C,n)) = {((Gauge C,n) * i,k1)} )

take k1 ; :: thesis: ( j <= j1 & j1 <= k1 & k1 <= k & (LSeg ((Gauge C,n) * i,j1),((Gauge C,n) * i,k1)) /\ (L~ (Lower_Seq C,n)) = {((Gauge C,n) * i,j1)} & (LSeg ((Gauge C,n) * i,j1),((Gauge C,n) * i,k1)) /\ (L~ (Upper_Seq C,n)) = {((Gauge C,n) * i,k1)} )
thus ( j <= j1 & j1 <= k1 & k1 <= k ) by A11, A19; :: thesis: ( (LSeg ((Gauge C,n) * i,j1),((Gauge C,n) * i,k1)) /\ (L~ (Lower_Seq C,n)) = {((Gauge C,n) * i,j1)} & (LSeg ((Gauge C,n) * i,j1),((Gauge C,n) * i,k1)) /\ (L~ (Upper_Seq C,n)) = {((Gauge C,n) * i,k1)} )
A24: |[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]| `2 <= |[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]| `2 by A1, A13, A15, A19, A21, A23, SPRECT_3:24;
set X = (LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k1)) /\ (L~ (Lower_Seq C,n));
reconsider X1 = (LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k1)) /\ (L~ (Lower_Seq C,n)) as non empty compact Subset of (TOP-REAL 2) by A3, A17, PSCOMP_1:64, XBOOLE_0:def 4;
consider pp being set such that
A25: pp in N-most X1 by XBOOLE_0:def 1;
reconsider pp = pp as Point of (TOP-REAL 2) by A25;
A26: pp in (LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k1)) /\ (L~ (Lower_Seq C,n)) by A25, XBOOLE_0:def 4;
then A27: pp in L~ (Lower_Seq C,n) by XBOOLE_0:def 4;
A28: pp in LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k1) by A26, XBOOLE_0:def 4;
A29: ((Gauge C,n) * i,j) `1 = |[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]| `1 by A1, A2, A8, A14, A15, GOBOARD5:3;
then LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]| is vertical by SPPOL_1:37;
then A30: pp `1 = |[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]| `1 by A14, A15, A22, A23, A28, SPPOL_1:64;
|[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]| `2 = N-bound ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k1)) /\ (L~ (Lower_Seq C,n))) by A15, A20, A23, SPRECT_1:50
.= (N-min ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k1)) /\ (L~ (Lower_Seq C,n)))) `2 by EUCLID:56
.= pp `2 by A25, PSCOMP_1:98 ;
then A31: |[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]| in L~ (Lower_Seq C,n) by A27, A30, TOPREAL3:11;
for x being set holds
( x in (LSeg |[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|,|[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)) iff x = |[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]| )
proof
let x be set ; :: thesis: ( x in (LSeg |[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|,|[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)) iff x = |[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]| )
thus ( x in (LSeg |[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|,|[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)) implies x = |[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]| ) :: thesis: ( x = |[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]| implies x in (LSeg |[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|,|[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)) )
proof
assume A32: x in (LSeg |[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|,|[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)) ; :: thesis: x = |[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]|
then reconsider pp = x as Point of (TOP-REAL 2) ;
A33: pp in LSeg |[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|,|[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]| by A32, XBOOLE_0:def 4;
then A34: pp `1 = |[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]| `1 by A14, A15, A22, A23, GOBOARD7:5;
A35: pp `2 >= |[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]| `2 by A24, A33, TOPREAL1:10;
reconsider EE = (LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)) as compact Subset of (TOP-REAL 2) by PSCOMP_1:64;
reconsider E0 = proj2 .: EE as compact Subset of REAL by JCT_MISC:24;
A36: ((Gauge C,n) * i,j) `1 = |[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]| `1 by A1, A2, A8, A22, A23, GOBOARD5:3;
((Gauge C,n) * i,j) `2 <= |[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]| `2 by A1, A2, A19, A21, A23, SPRECT_3:24;
then A37: |[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]| in LSeg |[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|,((Gauge C,n) * i,j) by A14, A15, A22, A23, A24, A36, GOBOARD7:8;
|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]| in LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]| by RLTOPSP1:69;
then A38: LSeg |[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|,|[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]| c= LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]| by A37, TOPREAL1:12;
E0 is bounded by RCOMP_1:28;
then A39: E0 is bounded_above by XXREAL_2:def 11;
pp in L~ (Lower_Seq C,n) by A32, XBOOLE_0:def 4;
then pp in EE by A33, A38, XBOOLE_0:def 4;
then proj2 . pp in E0 by FUNCT_2:43;
then pp `2 in E0 by PSCOMP_1:def 29;
then |[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]| `2 >= pp `2 by A20, A23, A39, SEQ_4:def 4;
then pp `2 = |[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]| `2 by A35, XXREAL_0:1;
hence x = |[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]| by A34, TOPREAL3:11; :: thesis: verum
end;
assume A40: x = |[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]| ; :: thesis: x in (LSeg |[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|,|[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n))
then x in LSeg |[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|,|[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]| by RLTOPSP1:69;
hence x in (LSeg |[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|,|[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)) by A31, A40, XBOOLE_0:def 4; :: thesis: verum
end;
hence (LSeg ((Gauge C,n) * i,j1),((Gauge C,n) * i,k1)) /\ (L~ (Lower_Seq C,n)) = {((Gauge C,n) * i,j1)} by A15, A23, TARSKI:def 1; :: thesis: (LSeg ((Gauge C,n) * i,j1),((Gauge C,n) * i,k1)) /\ (L~ (Upper_Seq C,n)) = {((Gauge C,n) * i,k1)}
set X = (LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n));
reconsider X1 = (LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)) as non empty compact Subset of (TOP-REAL 2) by A4, A6, PSCOMP_1:64, XBOOLE_0:def 4;
consider pp being set such that
A41: pp in S-most X1 by XBOOLE_0:def 1;
reconsider pp = pp as Point of (TOP-REAL 2) by A41;
A42: pp in (LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)) by A41, XBOOLE_0:def 4;
then A43: pp in L~ (Upper_Seq C,n) by XBOOLE_0:def 4;
A44: pp in LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k) by A42, XBOOLE_0:def 4;
((Gauge C,n) * i,j) `1 = ((Gauge C,n) * i,1) `1 by A1, A2, A8, GOBOARD5:3
.= ((Gauge C,n) * i,k) `1 by A1, A2, A10, GOBOARD5:3 ;
then LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k) is vertical by SPPOL_1:37;
then A45: pp `1 = |[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]| `1 by A29, A44, SPPOL_1:64;
|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]| `2 = S-bound ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n))) by A12, A15, SPRECT_1:49
.= (S-min ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))) `2 by EUCLID:56
.= pp `2 by A41, PSCOMP_1:118 ;
then A46: |[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]| in L~ (Upper_Seq C,n) by A43, A45, TOPREAL3:11;
for x being set holds
( x in (LSeg |[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|,|[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]|) /\ (L~ (Upper_Seq C,n)) iff x = |[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]| )
proof
let x be set ; :: thesis: ( x in (LSeg |[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|,|[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]|) /\ (L~ (Upper_Seq C,n)) iff x = |[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]| )
thus ( x in (LSeg |[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|,|[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]|) /\ (L~ (Upper_Seq C,n)) implies x = |[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]| ) :: thesis: ( x = |[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]| implies x in (LSeg |[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|,|[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]|) /\ (L~ (Upper_Seq C,n)) )
proof
assume A47: x in (LSeg |[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|,|[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]|) /\ (L~ (Upper_Seq C,n)) ; :: thesis: x = |[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|
then reconsider pp = x as Point of (TOP-REAL 2) ;
A48: pp in LSeg |[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|,|[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]| by A47, XBOOLE_0:def 4;
then A49: pp `1 = |[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]| `1 by A14, A15, A22, A23, GOBOARD7:5;
A50: pp `2 <= |[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]| `2 by A24, A48, TOPREAL1:10;
reconsider EE = (LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)) as compact Subset of (TOP-REAL 2) by PSCOMP_1:64;
reconsider E0 = proj2 .: EE as compact Subset of REAL by JCT_MISC:24;
A51: ((Gauge C,n) * i,j) `1 = |[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]| `1 by A1, A2, A8, A22, A23, GOBOARD5:3;
A52: ((Gauge C,n) * i,k) `1 = |[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]| `1 by A1, A2, A10, A22, A23, GOBOARD5:3;
A53: ((Gauge C,n) * i,j) `2 <= |[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]| `2 by A1, A2, A19, A21, A23, SPRECT_3:24;
j1 <= k by A11, A19, XXREAL_0:2;
then |[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]| `2 <= ((Gauge C,n) * i,k) `2 by A1, A2, A21, A23, SPRECT_3:24;
then A54: |[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]| in LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k) by A51, A52, A53, GOBOARD7:8;
A55: ((Gauge C,n) * i,j) `1 = |[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]| `1 by A1, A2, A8, A14, A15, GOBOARD5:3;
A56: ((Gauge C,n) * i,k) `1 = |[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]| `1 by A1, A2, A10, A14, A15, GOBOARD5:3;
A57: ((Gauge C,n) * i,j) `2 <= |[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]| `2 by A1, A2, A11, A13, A15, SPRECT_3:24;
|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]| `2 <= ((Gauge C,n) * i,k) `2 by A1, A2, A11, A13, A15, SPRECT_3:24;
then |[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]| in LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k) by A55, A56, A57, GOBOARD7:8;
then A58: LSeg |[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|,|[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]| c= LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k) by A54, TOPREAL1:12;
E0 is bounded by RCOMP_1:28;
then A59: E0 is bounded_below by XXREAL_2:def 11;
pp in L~ (Upper_Seq C,n) by A47, XBOOLE_0:def 4;
then pp in EE by A48, A58, XBOOLE_0:def 4;
then proj2 . pp in E0 by FUNCT_2:43;
then pp `2 in E0 by PSCOMP_1:def 29;
then |[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]| `2 <= pp `2 by A12, A15, A59, SEQ_4:def 5;
then pp `2 = |[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]| `2 by A50, XXREAL_0:1;
hence x = |[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]| by A49, TOPREAL3:11; :: thesis: verum
end;
assume A60: x = |[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]| ; :: thesis: x in (LSeg |[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|,|[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]|) /\ (L~ (Upper_Seq C,n))
then x in LSeg |[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|,|[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]| by RLTOPSP1:69;
hence x in (LSeg |[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|,|[(((Gauge C,n) * i,1) `1 ),(sup (proj2 .: ((LSeg ((Gauge C,n) * i,j),|[(((Gauge C,n) * i,1) `1 ),(inf (proj2 .: ((LSeg ((Gauge C,n) * i,j),((Gauge C,n) * i,k)) /\ (L~ (Upper_Seq C,n)))))]|) /\ (L~ (Lower_Seq C,n)))))]|) /\ (L~ (Upper_Seq C,n)) by A46, A60, XBOOLE_0:def 4; :: thesis: verum
end;
hence (LSeg ((Gauge C,n) * i,j1),((Gauge C,n) * i,k1)) /\ (L~ (Upper_Seq C,n)) = {((Gauge C,n) * i,k1)} by A15, A23, TARSKI:def 1; :: thesis: verum