let n be Nat; :: thesis: for A being affinely-independent Subset of (TOP-REAL n) st card A = n + 1 holds
ind (conv A) = n

let A be affinely-independent Subset of (TOP-REAL n); :: thesis: ( card A = n + 1 implies ind (conv A) = n )
set TR = TOP-REAL n;
assume A1: card A = n + 1 ; :: thesis: ind (conv A) = n
set C = conv A;
A2: ind (conv A) >= n
proof
set E = the Enumeration of A;
assume A3: ind (conv A) < n ; :: thesis: contradiction
not A is empty by A1;
then reconsider C = conv A as non empty Subset of (TOP-REAL n) ;
ind C is natural ;
then reconsider n1 = n - 1 as Nat by A3;
deffunc H1( object ) -> Element of bool the carrier of (TOP-REAL n) = C \ (conv (A \ {( the Enumeration of A . $1)}));
reconsider c = C as Subset of TopStruct(# the carrier of (TOP-REAL n), the topology of (TOP-REAL n) #) ;
set TRC = (TOP-REAL n) | C;
set carr = the carrier of ((TOP-REAL n) | C);
A4: ( TopStruct(# the carrier of (TOP-REAL n), the topology of (TOP-REAL n) #) = TopSpaceMetr (Euclid n) & TopStruct(# the carrier of ((TOP-REAL n) | C), the topology of ((TOP-REAL n) | C) #) = TopStruct(# the carrier of (TOP-REAL n), the topology of (TOP-REAL n) #) | c ) by EUCLID:def 8, PRE_TOPC:36;
consider f being FinSequence such that
A5: ( len f = len the Enumeration of A & ( for k being Nat st k in dom f holds
f . k = H1(k) ) ) from FINSEQ_1:sch 2();
A6: [#] ((TOP-REAL n) | C) = C by PRE_TOPC:def 5;
rng f c= bool the carrier of ((TOP-REAL n) | C)
proof
let y be object ; :: according to TARSKI:def 3 :: thesis: ( not y in rng f or y in bool the carrier of ((TOP-REAL n) | C) )
assume y in rng f ; :: thesis: y in bool the carrier of ((TOP-REAL n) | C)
then consider x being object such that
A7: x in dom f and
A8: f . x = y by FUNCT_1:def 3;
f . x = H1(x) by A5, A7;
then f . x c= C by XBOOLE_1:36;
hence y in bool the carrier of ((TOP-REAL n) | C) by A6, A8; :: thesis: verum
end;
then reconsider R = rng f as finite Subset-Family of ((TOP-REAL n) | C) ;
A9: rng the Enumeration of A = A by RLAFFIN3:def 1;
then A10: len the Enumeration of A = card A by FINSEQ_4:62;
A11: dom f = dom the Enumeration of A by A5, FINSEQ_3:29;
the carrier of ((TOP-REAL n) | C) c= union R
proof
let x be object ; :: according to TARSKI:def 3 :: thesis: ( not x in the carrier of ((TOP-REAL n) | C) or x in union R )
assume A12: x in the carrier of ((TOP-REAL n) | C) ; :: thesis: x in union R
assume A13: not x in union R ; :: thesis: contradiction
now :: thesis: for y being set st y in A holds
(x |-- A) . y = 0
let y be set ; :: thesis: ( y in A implies (x |-- A) . y = 0 )
assume A14: y in A ; :: thesis: (x |-- A) . y = 0
then consider n being object such that
A15: n in dom the Enumeration of A and
A16: the Enumeration of A . n = y by A9, FUNCT_1:def 3;
reconsider n = n as Nat by A15;
f . n = H1(n) by A5, A11, A15;
then H1(n) in R by A11, A15, FUNCT_1:def 3;
then not x in H1(n) by A13, TARSKI:def 4;
then ( conv (A \ {( the Enumeration of A . n)}) c= Affin (A \ {( the Enumeration of A . n)}) & x in conv (A \ {( the Enumeration of A . n)}) ) by A6, A12, RLAFFIN1:65, XBOOLE_0:def 5;
then A17: x |-- A = x |-- (A \ {( the Enumeration of A . n)}) by RLAFFIN1:77, XBOOLE_1:36;
( Carrier (x |-- (A \ {( the Enumeration of A . n)})) c= A \ {( the Enumeration of A . n)} & the Enumeration of A . n in {( the Enumeration of A . n)} ) by RLVECT_2:def 6, TARSKI:def 1;
then not the Enumeration of A . n in Carrier (x |-- (A \ {( the Enumeration of A . n)})) by XBOOLE_0:def 5;
hence (x |-- A) . y = 0 by A14, A16, A17, RLVECT_2:19; :: thesis: verum
end;
then A18: x in conv (A \ A) by A6, A12, RLAFFIN1:76;
A \ A = {} by XBOOLE_1:37;
hence contradiction by A18; :: thesis: verum
end;
then A19: R is Cover of ((TOP-REAL n) | C) by SETFAM_1:def 11;
now :: thesis: for U being Subset of ((TOP-REAL n) | C) st U in R holds
U is open
let U be Subset of ((TOP-REAL n) | C); :: thesis: ( U in R implies U is open )
assume U in R ; :: thesis: U is open
then consider x being object such that
A20: ( x in dom f & f . x = U ) by FUNCT_1:def 3;
reconsider cAE = conv (A \ {( the Enumeration of A . x)}) as Subset of ((TOP-REAL n) | C) by A6, RLAFFIN1:3, XBOOLE_1:36;
A \ {( the Enumeration of A . x)} is affinely-independent by RLAFFIN1:43, XBOOLE_1:36;
then A21: cAE is closed by TSEP_1:8;
U = cAE ` by A6, A5, A20;
hence U is open by A21; :: thesis: verum
end;
then A22: ( ind ((TOP-REAL n) | C) = ind C & R is open ) by TOPDIM_1:17, TOPS_2:def 1;
ind C < n1 + 1 by A3;
then ind C <= n1 by NAT_1:13;
then consider G being finite Subset-Family of ((TOP-REAL n) | C) such that
A23: G is open and
A24: G is Cover of ((TOP-REAL n) | C) and
A25: G is_finer_than R and
card G <= (card R) * (n1 + 1) and
A26: order G <= n1 by A4, A22, A19, TOPDIM_2:23;
defpred S1[ Nat, set , set ] means $3 = { g where g is Subset of ((TOP-REAL n) | C) : ( g in G & ( g c= f . ($1 + 1) or g in $2 ) ) } ;
defpred S2[ set ] means ( $1 in G & $1 c= f . 1 );
consider G0 being Subset-Family of ((TOP-REAL n) | C) such that
A27: for x being set holds
( x in G0 iff ( x in bool the carrier of ((TOP-REAL n) | C) & S2[x] ) ) from SUBSET_1:sch 1();
A28: for k being Nat st 1 <= k & k < len the Enumeration of A holds
for x being Element of bool (bool the carrier of ((TOP-REAL n) | C)) ex y being Element of bool (bool the carrier of ((TOP-REAL n) | C)) st S1[k,x,y]
proof
let k be Nat; :: thesis: ( 1 <= k & k < len the Enumeration of A implies for x being Element of bool (bool the carrier of ((TOP-REAL n) | C)) ex y being Element of bool (bool the carrier of ((TOP-REAL n) | C)) st S1[k,x,y] )
assume that
1 <= k and
k < len the Enumeration of A ; :: thesis: for x being Element of bool (bool the carrier of ((TOP-REAL n) | C)) ex y being Element of bool (bool the carrier of ((TOP-REAL n) | C)) st S1[k,x,y]
let x be Element of bool (bool the carrier of ((TOP-REAL n) | C)); :: thesis: ex y being Element of bool (bool the carrier of ((TOP-REAL n) | C)) st S1[k,x,y]
set y = { g where g is Subset of ((TOP-REAL n) | C) : ( g in G & ( g c= f . (k + 1) or g in x ) ) } ;
{ g where g is Subset of ((TOP-REAL n) | C) : ( g in G & ( g c= f . (k + 1) or g in x ) ) } c= bool the carrier of ((TOP-REAL n) | C)
proof
let z be object ; :: according to TARSKI:def 3 :: thesis: ( not z in { g where g is Subset of ((TOP-REAL n) | C) : ( g in G & ( g c= f . (k + 1) or g in x ) ) } or z in bool the carrier of ((TOP-REAL n) | C) )
assume z in { g where g is Subset of ((TOP-REAL n) | C) : ( g in G & ( g c= f . (k + 1) or g in x ) ) } ; :: thesis: z in bool the carrier of ((TOP-REAL n) | C)
then ex g being Subset of ((TOP-REAL n) | C) st
( g = z & g in G & ( g c= f . (k + 1) or g in x ) ) ;
hence z in bool the carrier of ((TOP-REAL n) | C) ; :: thesis: verum
end;
hence ex y being Element of bool (bool the carrier of ((TOP-REAL n) | C)) st S1[k,x,y] ; :: thesis: verum
end;
consider p being FinSequence of bool (bool the carrier of ((TOP-REAL n) | C)) such that
A29: len p = len the Enumeration of A and
A30: ( p /. 1 = G0 or len the Enumeration of A = 0 ) and
A31: for k being Nat st 1 <= k & k < len the Enumeration of A holds
S1[k,p /. k,p /. (k + 1)] from NAT_2:sch 1(A28);
defpred S3[ Nat, object ] means ( ( $1 = 1 implies $2 = union G0 ) & ( $1 <> 1 implies $2 = union ((p . $1) \ (p . ($1 - 1))) ) );
A32: for k being Nat st k in Seg (len the Enumeration of A) holds
ex x being object st S3[k,x]
proof
let k be Nat; :: thesis: ( k in Seg (len the Enumeration of A) implies ex x being object st S3[k,x] )
( k = 1 or k <> 1 ) ;
hence ( k in Seg (len the Enumeration of A) implies ex x being object st S3[k,x] ) ; :: thesis: verum
end;
consider h being FinSequence such that
A33: dom h = Seg (len the Enumeration of A) and
A34: for k being Nat st k in Seg (len the Enumeration of A) holds
S3[k,h . k] from FINSEQ_1:sch 1(A32);
A35: dom p = Seg (len the Enumeration of A) by A29, FINSEQ_1:def 3;
rng h c= bool the carrier of ((TOP-REAL n) | C)
proof
let y be object ; :: according to TARSKI:def 3 :: thesis: ( not y in rng h or y in bool the carrier of ((TOP-REAL n) | C) )
assume y in rng h ; :: thesis: y in bool the carrier of ((TOP-REAL n) | C)
then consider x being object such that
A36: x in dom h and
A37: h . x = y by FUNCT_1:def 3;
reconsider x = x as Nat by A36;
p . x in rng p by A35, A33, A36, FUNCT_1:def 3;
then reconsider px = p . x as Subset-Family of ((TOP-REAL n) | C) ;
( y = union G0 or y = union (px \ (p . (x - 1))) ) by A33, A34, A36, A37;
hence y in bool the carrier of ((TOP-REAL n) | C) ; :: thesis: verum
end;
then reconsider h = h as FinSequence of bool the carrier of ((TOP-REAL n) | C) by FINSEQ_1:def 4;
A38: A is non empty affinely-independent Subset of (TOP-REAL n) by A1;
A39: 1 <= n + 1 by NAT_1:11;
the carrier of ((TOP-REAL n) | C) c= union (rng h)
proof
let x be object ; :: according to TARSKI:def 3 :: thesis: ( not x in the carrier of ((TOP-REAL n) | C) or x in union (rng h) )
assume x in the carrier of ((TOP-REAL n) | C) ; :: thesis: x in union (rng h)
then x in union G by A24, SETFAM_1:45;
then consider y being set such that
A40: x in y and
A41: y in G by TARSKI:def 4;
consider z being set such that
A42: z in R and
A43: y c= z by A25, A41, SETFAM_1:def 2;
consider k being object such that
A44: k in dom f and
A45: f . k = z by A42, FUNCT_1:def 3;
reconsider k = k as Nat by A44;
A46: k >= 1 by A44, FINSEQ_3:25;
A47: len the Enumeration of A >= k by A5, A44, FINSEQ_3:25;
per cases ( k = 1 or y in G0 or ( k > 1 & not y in G0 ) ) by A46, XXREAL_0:1;
suppose A52: ( k > 1 & not y in G0 ) ; :: thesis: x in union (rng h)
defpred S4[ Nat] means ( $1 > 1 & $1 <= len the Enumeration of A & y c= f . $1 );
A53: ex k being Nat st S4[k] by A43, A45, A47, A52;
consider m being Nat such that
A54: ( S4[m] & ( for n being Nat st S4[n] holds
m <= n ) ) from NAT_1:sch 5(A53);
reconsider m1 = m - 1 as Element of NAT by A54, NAT_1:20;
defpred S5[ Nat] means ( 1 <= $1 & $1 <= m1 implies not y in p /. $1 );
m1 + 1 <= len the Enumeration of A by A54;
then A55: m1 < len the Enumeration of A by NAT_1:13;
A56: for n being Nat st S5[n] holds
S5[n + 1]
proof
let n be Nat; :: thesis: ( S5[n] implies S5[n + 1] )
assume A57: S5[n] ; :: thesis: S5[n + 1]
set n1 = n + 1;
assume that
1 <= n + 1 and
A58: n + 1 <= m1 ; :: thesis: not y in p /. (n + 1)
n < m1 by A58, NAT_1:13;
then A59: n < len the Enumeration of A by A55, XXREAL_0:2;
per cases ( n = 0 or n >= 1 ) by NAT_1:14;
suppose n = 0 ; :: thesis: not y in p /. (n + 1)
hence not y in p /. (n + 1) by A1, A9, A30, A52, FINSEQ_4:62; :: thesis: verum
end;
suppose A60: n >= 1 ; :: thesis: not y in p /. (n + 1)
assume A61: y in p /. (n + 1) ; :: thesis: contradiction
p /. (n + 1) = { g where g is Subset of ((TOP-REAL n) | C) : ( g in G & ( g c= f . (n + 1) or g in p /. n ) ) } by A31, A59, A60;
then ex g being Subset of ((TOP-REAL n) | C) st
( y = g & g in G & ( g c= f . (n + 1) or g in p /. n ) ) by A61;
then S4[n + 1] by A55, A57, A58, A60, NAT_1:13, XXREAL_0:2;
then m <= n + 1 by A54;
then m1 + 1 <= m1 by A58, XXREAL_0:2;
hence contradiction by NAT_1:13; :: thesis: verum
end;
end;
end;
A62: S5[ 0 ] ;
A63: for n being Nat holds S5[n] from NAT_1:sch 2(A62, A56);
A64: m in dom p by A29, A54, FINSEQ_3:25;
then A65: h . m in rng h by A35, A33, FUNCT_1:def 3;
m1 + 1 > 1 by A54;
then A66: m1 >= 1 by NAT_1:13;
then A67: p /. m = { g where g is Subset of ((TOP-REAL n) | C) : ( g in G & ( g c= f . (m1 + 1) or g in p /. m1 ) ) } by A31, A55;
m1 in dom p by A29, A66, A55, FINSEQ_3:25;
then p . m1 = p /. m1 by PARTFUN1:def 6;
then A68: not y in p . m1 by A66, A63;
p . m = p /. m by A64, PARTFUN1:def 6;
then y in p . m by A41, A54, A67;
then y in (p . m) \ (p . m1) by A68, XBOOLE_0:def 5;
then A69: x in union ((p . m) \ (p . m1)) by A40, TARSKI:def 4;
h . m = union ((p . m) \ (p . m1)) by A35, A34, A54, A64;
hence x in union (rng h) by A69, A65, TARSKI:def 4; :: thesis: verum
end;
end;
end;
then A70: rng h is Cover of ((TOP-REAL n) | C) by SETFAM_1:def 11;
now :: thesis: for A being Subset of ((TOP-REAL n) | C) st A in rng h holds
A is open
let A be Subset of ((TOP-REAL n) | C); :: thesis: ( A in rng h implies b1 is open )
assume A in rng h ; :: thesis: b1 is open
then consider k being object such that
A71: k in dom h and
A72: h . k = A by FUNCT_1:def 3;
reconsider k = k as Nat by A71;
A73: k >= 1 by A33, A71, FINSEQ_1:1;
per cases ( k = 1 or k > 1 ) by A73, XXREAL_0:1;
suppose A76: k > 1 ; :: thesis: b1 is open
then reconsider k1 = k - 1 as Element of NAT by NAT_1:20;
k1 + 1 > 1 by A76;
then A77: k1 >= 1 by NAT_1:13;
k1 + 1 <= len the Enumeration of A by A33, A71, FINSEQ_1:1;
then A78: k1 < len the Enumeration of A by NAT_1:13;
then k1 in dom p by A29, A77, FINSEQ_3:25;
then A79: p . k1 = p /. k1 by PARTFUN1:def 6;
A80: S1[k1,p /. k1,p /. (k1 + 1)] by A31, A77, A78;
p /. k c= G
proof
let x be object ; :: according to TARSKI:def 3 :: thesis: ( not x in p /. k or x in G )
assume x in p /. k ; :: thesis: x in G
then ex g being Subset of ((TOP-REAL n) | C) st
( x = g & g in G & ( g c= f . k or g in p /. k1 ) ) by A80;
hence x in G ; :: thesis: verum
end;
then p /. k is open by A23, TOPS_2:11;
then A81: (p /. k) \ (p /. (k - 1)) is open by TOPS_2:15;
A82: p . k = p /. k by A35, A33, A71, PARTFUN1:def 6;
A = union ((p . k) \ (p . (k - 1))) by A33, A34, A71, A72, A76;
hence A is open by A82, A81, A79, TOPS_2:19; :: thesis: verum
end;
end;
end;
then A83: rng h is open by TOPS_2:def 1;
(TOP-REAL n) | C is compact by COMPTS_1:3;
then consider gx being Subset-Family of ((TOP-REAL n) | C) such that
gx is open and
A84: gx is Cover of ((TOP-REAL n) | C) and
A85: clf gx is_finer_than rng h and
A86: gx is locally_finite by A4, A70, A83, PCOMPS_1:22, PCOMPS_2:3;
set cgx = clf gx;
defpred S4[ object , object ] means $2 = union { u where u is Subset of ((TOP-REAL n) | C) : ( u in clf gx & u c= h . $1 ) } ;
A87: for k being Nat st k in Seg (len the Enumeration of A) holds
ex x being Element of bool the carrier of ((TOP-REAL n) | C) st S4[k,x]
proof
let k be Nat; :: thesis: ( k in Seg (len the Enumeration of A) implies ex x being Element of bool the carrier of ((TOP-REAL n) | C) st S4[k,x] )
set U = { u where u is Subset of ((TOP-REAL n) | C) : ( u in clf gx & u c= h . k ) } ;
{ u where u is Subset of ((TOP-REAL n) | C) : ( u in clf gx & u c= h . k ) } c= bool the carrier of ((TOP-REAL n) | C)
proof
let x be object ; :: according to TARSKI:def 3 :: thesis: ( not x in { u where u is Subset of ((TOP-REAL n) | C) : ( u in clf gx & u c= h . k ) } or x in bool the carrier of ((TOP-REAL n) | C) )
assume x in { u where u is Subset of ((TOP-REAL n) | C) : ( u in clf gx & u c= h . k ) } ; :: thesis: x in bool the carrier of ((TOP-REAL n) | C)
then ex u being Subset of ((TOP-REAL n) | C) st
( u = x & u in clf gx & u c= h . k ) ;
hence x in bool the carrier of ((TOP-REAL n) | C) ; :: thesis: verum
end;
then reconsider U = { u where u is Subset of ((TOP-REAL n) | C) : ( u in clf gx & u c= h . k ) } as Subset-Family of ((TOP-REAL n) | C) ;
union U is Subset of ((TOP-REAL n) | C) ;
hence ( k in Seg (len the Enumeration of A) implies ex x being Element of bool the carrier of ((TOP-REAL n) | C) st S4[k,x] ) ; :: thesis: verum
end;
consider GX being FinSequence of bool the carrier of ((TOP-REAL n) | C) such that
A88: ( dom GX = Seg (len the Enumeration of A) & ( for k being Nat st k in Seg (len the Enumeration of A) holds
S4[k,GX . k] ) ) from FINSEQ_1:sch 5(A87);
A89: for i being Nat st i in dom GX holds
GX . i c= h . i
proof
let i be Nat; :: thesis: ( i in dom GX implies GX . i c= h . i )
set U = { u where u is Subset of ((TOP-REAL n) | C) : ( u in clf gx & u c= h . i ) } ;
now :: thesis: for x being set st x in { u where u is Subset of ((TOP-REAL n) | C) : ( u in clf gx & u c= h . i ) } holds
x c= h . i
let x be set ; :: thesis: ( x in { u where u is Subset of ((TOP-REAL n) | C) : ( u in clf gx & u c= h . i ) } implies x c= h . i )
assume x in { u where u is Subset of ((TOP-REAL n) | C) : ( u in clf gx & u c= h . i ) } ; :: thesis: x c= h . i
then ex u being Subset of ((TOP-REAL n) | C) st
( x = u & u in clf gx & u c= h . i ) ;
hence x c= h . i ; :: thesis: verum
end;
then A90: union { u where u is Subset of ((TOP-REAL n) | C) : ( u in clf gx & u c= h . i ) } c= h . i by ZFMISC_1:76;
assume i in dom GX ; :: thesis: GX . i c= h . i
hence GX . i c= h . i by A88, A90; :: thesis: verum
end;
A91: dom the Enumeration of A = Seg (len the Enumeration of A) by FINSEQ_1:def 3;
A92: for k being Nat st k in Seg (len the Enumeration of A) holds
h . k misses conv (A \ {( the Enumeration of A . k)})
proof
let k be Nat; :: thesis: ( k in Seg (len the Enumeration of A) implies h . k misses conv (A \ {( the Enumeration of A . k)}) )
assume A93: k in Seg (len the Enumeration of A) ; :: thesis: h . k misses conv (A \ {( the Enumeration of A . k)})
then A94: k >= 1 by FINSEQ_1:1;
A95: S3[k,h . k] by A34, A93;
assume h . k meets conv (A \ {( the Enumeration of A . k)}) ; :: thesis: contradiction
then consider x being object such that
A96: x in h . k and
A97: x in conv (A \ {( the Enumeration of A . k)}) by XBOOLE_0:3;
per cases ( k = 1 or k > 1 ) by A94, XXREAL_0:1;
suppose A98: k = 1 ; :: thesis: contradiction
then consider y being set such that
A99: x in y and
A100: y in G0 by A95, A96, TARSKI:def 4;
S2[y] by A27, A100;
then y c= H1(k) by A5, A11, A91, A93, A98;
hence contradiction by A97, A99, XBOOLE_0:def 5; :: thesis: verum
end;
suppose A101: k > 1 ; :: thesis: contradiction
then reconsider k1 = k - 1 as Element of NAT by NAT_1:20;
len the Enumeration of A >= k1 + 1 by A93, FINSEQ_1:1;
then A102: len the Enumeration of A > k1 by NAT_1:13;
k1 + 1 > 1 by A101;
then A103: k1 >= 1 by NAT_1:13;
then A104: S1[k1,p /. k1,p /. (k1 + 1)] by A31, A102;
k1 in dom p by A29, A103, A102, FINSEQ_3:25;
then A105: p /. k1 = p . k1 by PARTFUN1:def 6;
A106: p /. k = p . k by A35, A93, PARTFUN1:def 6;
consider y being set such that
A107: x in y and
A108: y in (p . k) \ (p . (k - 1)) by A95, A96, A101, TARSKI:def 4;
y in p . k by A108;
then consider g being Subset of ((TOP-REAL n) | C) such that
A109: y = g and
g in G and
A110: ( g c= f . k or g in p . k1 ) by A104, A106, A105;
f . k = H1(k) by A5, A11, A91, A93;
hence contradiction by A97, A107, A108, A109, A110, XBOOLE_0:def 5; :: thesis: verum
end;
end;
end;
the carrier of ((TOP-REAL n) | C) c= union (rng GX)
proof
let x be object ; :: according to TARSKI:def 3 :: thesis: ( not x in the carrier of ((TOP-REAL n) | C) or x in union (rng GX) )
assume A111: x in the carrier of ((TOP-REAL n) | C) ; :: thesis: x in union (rng GX)
( union gx = the carrier of ((TOP-REAL n) | C) & union gx c= union (clf gx) ) by A84, PCOMPS_1:19, SETFAM_1:45;
then consider y being set such that
A112: x in y and
A113: y in clf gx by A111, TARSKI:def 4;
consider r being set such that
A114: r in rng h and
A115: y c= r by A85, A113, SETFAM_1:def 2;
consider k being object such that
A116: k in dom h and
A117: h . k = r by A114, FUNCT_1:def 3;
A118: S4[k,GX . k] by A33, A88, A116;
A119: GX . k in rng GX by A33, A88, A116, FUNCT_1:def 3;
y in { u where u is Subset of ((TOP-REAL n) | C) : ( u in clf gx & u c= h . k ) } by A113, A115, A117;
then x in GX . k by A112, A118, TARSKI:def 4;
hence x in union (rng GX) by A119, TARSKI:def 4; :: thesis: verum
end;
then A120: rng GX is Cover of ((TOP-REAL n) | C) by SETFAM_1:def 11;
A121: for S being Subset of (dom GX) holds conv ( the Enumeration of A .: S) c= union (GX .: S)
proof
let S be Subset of (dom GX); :: thesis: conv ( the Enumeration of A .: S) c= union (GX .: S)
A122: rng GX = GX .: (dom GX) by RELAT_1:113;
A123: union (rng GX) = the carrier of ((TOP-REAL n) | C) by A120, SETFAM_1:45;
per cases ( S = dom GX or not dom GX c= S ) by XBOOLE_0:def 10;
suppose S = dom GX ; :: thesis: conv ( the Enumeration of A .: S) c= union (GX .: S)
hence conv ( the Enumeration of A .: S) c= union (GX .: S) by A6, A9, A91, A88, A122, A123, RELAT_1:113; :: thesis: verum
end;
suppose A124: not dom GX c= S ; :: thesis: conv ( the Enumeration of A .: S) c= union (GX .: S)
set U = { (conv (A \ {( the Enumeration of A . i)})) where i is Element of NAT : i in (dom the Enumeration of A) \ S } ;
not (dom GX) \ S is empty by A124, XBOOLE_1:37;
then A125: conv ( the Enumeration of A .: S) = meet { (conv (A \ {( the Enumeration of A . i)})) where i is Element of NAT : i in (dom the Enumeration of A) \ S } by A91, A88, Th12;
A126: meet { (conv (A \ {( the Enumeration of A . i)})) where i is Element of NAT : i in (dom the Enumeration of A) \ S } misses union (GX .: ((dom the Enumeration of A) \ S))
proof
assume meet { (conv (A \ {( the Enumeration of A . i)})) where i is Element of NAT : i in (dom the Enumeration of A) \ S } meets union (GX .: ((dom the Enumeration of A) \ S)) ; :: thesis: contradiction
then consider x being object such that
A127: x in meet { (conv (A \ {( the Enumeration of A . i)})) where i is Element of NAT : i in (dom the Enumeration of A) \ S } and
A128: x in union (GX .: ((dom the Enumeration of A) \ S)) by XBOOLE_0:3;
consider y being set such that
A129: x in y and
A130: y in GX .: ((dom the Enumeration of A) \ S) by A128, TARSKI:def 4;
consider i being object such that
A131: i in dom GX and
A132: i in (dom the Enumeration of A) \ S and
A133: GX . i = y by A130, FUNCT_1:def 6;
reconsider i = i as Element of NAT by A131;
conv (A \ {( the Enumeration of A . i)}) in { (conv (A \ {( the Enumeration of A . i)})) where i is Element of NAT : i in (dom the Enumeration of A) \ S } by A132;
then A134: meet { (conv (A \ {( the Enumeration of A . i)})) where i is Element of NAT : i in (dom the Enumeration of A) \ S } c= conv (A \ {( the Enumeration of A . i)}) by SETFAM_1:7;
y c= h . i by A89, A131, A133;
then h . i meets conv (A \ {( the Enumeration of A . i)}) by A127, A129, A134, XBOOLE_0:3;
hence contradiction by A92, A88, A131; :: thesis: verum
end;
dom GX = dom the Enumeration of A by A88, FINSEQ_1:def 3;
then rng GX = GX .: (S \/ ((dom the Enumeration of A) \ S)) by A122, XBOOLE_1:45
.= (GX .: S) \/ (GX .: ((dom the Enumeration of A) \ S)) by RELAT_1:120 ;
then A135: (union (GX .: S)) \/ (union (GX .: ((dom the Enumeration of A) \ S))) = C by A6, A123, ZFMISC_1:78;
conv ( the Enumeration of A .: S) c= C by A9, RELAT_1:111, RLAFFIN1:3;
hence conv ( the Enumeration of A .: S) c= union (GX .: S) by A125, A135, A126, XBOOLE_1:73; :: thesis: verum
end;
end;
end;
A136: clf gx is locally_finite by A86, PCOMPS_1:18;
now :: thesis: for A being Subset of ((TOP-REAL n) | C) st A in rng GX holds
A is closed
let A be Subset of ((TOP-REAL n) | C); :: thesis: ( A in rng GX implies A is closed )
assume A in rng GX ; :: thesis: A is closed
then consider k being object such that
A137: ( k in dom GX & GX . k = A ) by FUNCT_1:def 3;
set U = { u where u is Subset of ((TOP-REAL n) | C) : ( u in clf gx & u c= h . k ) } ;
A138: { u where u is Subset of ((TOP-REAL n) | C) : ( u in clf gx & u c= h . k ) } c= clf gx
proof
let x be object ; :: according to TARSKI:def 3 :: thesis: ( not x in { u where u is Subset of ((TOP-REAL n) | C) : ( u in clf gx & u c= h . k ) } or x in clf gx )
assume x in { u where u is Subset of ((TOP-REAL n) | C) : ( u in clf gx & u c= h . k ) } ; :: thesis: x in clf gx
then ex u being Subset of ((TOP-REAL n) | C) st
( x = u & u in clf gx & u c= h . k ) ;
hence x in clf gx ; :: thesis: verum
end;
then reconsider U = { u where u is Subset of ((TOP-REAL n) | C) : ( u in clf gx & u c= h . k ) } as Subset-Family of ((TOP-REAL n) | C) by XBOOLE_1:1;
U is closed by A138, PCOMPS_1:11, TOPS_2:12;
then union U is closed by A136, A138, PCOMPS_1:9, PCOMPS_1:21;
hence A is closed by A88, A137; :: thesis: verum
end;
then A139: rng GX is closed by TOPS_2:def 2;
len GX = card A by A10, A88, FINSEQ_1:def 3;
then not meet (rng GX) is empty by A139, A38, A121, Th22;
then consider I being object such that
A140: I in meet (rng GX) by XBOOLE_0:def 1;
defpred S5[ Nat, set ] means ( $2 in G & I in $2 & $2 in p . $1 & ( $1 <> 1 implies not $2 in p . ($1 - 1) ) );
A141: for k being Nat st k in Seg (len the Enumeration of A) holds
ex x being Element of bool the carrier of ((TOP-REAL n) | C) st S5[k,x]
proof
let k be Nat; :: thesis: ( k in Seg (len the Enumeration of A) implies ex x being Element of bool the carrier of ((TOP-REAL n) | C) st S5[k,x] )
assume A142: k in Seg (len the Enumeration of A) ; :: thesis: ex x being Element of bool the carrier of ((TOP-REAL n) | C) st S5[k,x]
then A143: k >= 1 by FINSEQ_1:1;
A144: k <= len the Enumeration of A by A142, FINSEQ_1:1;
A145: ( GX . k c= h . k & S3[k,h . k] ) by A34, A88, A89, A142;
GX . k in rng GX by A88, A142, FUNCT_1:def 3;
then meet (rng GX) c= GX . k by SETFAM_1:7;
then A146: I in GX . k by A140;
per cases ( k = 1 or k > 1 ) by A143, XXREAL_0:1;
suppose A147: k = 1 ; :: thesis: ex x being Element of bool the carrier of ((TOP-REAL n) | C) st S5[k,x]
1 in dom p by A1, A10, A35, A39, FINSEQ_1:1;
then A148: p . 1 = G0 by A1, A9, A30, FINSEQ_4:62, PARTFUN1:def 6;
consider g being set such that
A149: I in g and
A150: g in G0 by A146, A145, A147, TARSKI:def 4;
g in G by A27, A150;
hence ex x being Element of bool the carrier of ((TOP-REAL n) | C) st S5[k,x] by A147, A149, A150, A148; :: thesis: verum
end;
suppose A151: k > 1 ; :: thesis: ex x being Element of bool the carrier of ((TOP-REAL n) | C) st S5[k,x]
then reconsider k1 = k - 1 as Nat ;
A152: k1 + 1 = k ;
then A153: k1 < len the Enumeration of A by A144, NAT_1:13;
k1 >= 1 by A151, A152, NAT_1:13;
then A154: S1[k1,p /. k1,p /. k] by A31, A153;
A155: p . k = p /. k by A35, A142, PARTFUN1:def 6;
consider g being set such that
A156: I in g and
A157: g in (p . k) \ (p . (k - 1)) by A146, A145, A151, TARSKI:def 4;
A158: not g in p . (k - 1) by A157, XBOOLE_0:def 5;
g in p . k by A157;
then ex gg being Subset of ((TOP-REAL n) | C) st
( g = gg & gg in G & ( gg c= f . (k1 + 1) or gg in p /. k1 ) ) by A154, A155;
hence ex x being Element of bool the carrier of ((TOP-REAL n) | C) st S5[k,x] by A156, A157, A158; :: thesis: verum
end;
end;
end;
consider t being FinSequence of bool the carrier of ((TOP-REAL n) | C) such that
A159: ( dom t = Seg (len the Enumeration of A) & ( for k being Nat st k in Seg (len the Enumeration of A) holds
S5[k,t . k] ) ) from FINSEQ_1:sch 5(A141);
A160: now :: thesis: for i, j being Nat st i in dom t & j in dom t & i < j holds
not t . i = t . j
let i, j be Nat; :: thesis: ( i in dom t & j in dom t & i < j implies not t . i = t . j )
assume that
A161: i in dom t and
A162: j in dom t and
A163: i < j ; :: thesis: not t . i = t . j
A164: j <= len the Enumeration of A by A159, A162, FINSEQ_1:1;
defpred S6[ Nat] means ( i <= $1 & $1 < j implies t . i in p . $1 );
A165: S5[i,t . i] by A159, A161;
A166: 1 <= i by A159, A161, FINSEQ_1:1;
A167: for k being Nat st S6[k] holds
S6[k + 1]
proof
let k be Nat; :: thesis: ( S6[k] implies S6[k + 1] )
assume A168: S6[k] ; :: thesis: S6[k + 1]
set k1 = k + 1;
assume that
A169: i <= k + 1 and
A170: k + 1 < j ; :: thesis: t . i in p . (k + 1)
A171: k < j by A170, NAT_1:13;
per cases ( i = k + 1 or i <= k ) by A169, NAT_1:8;
suppose i = k + 1 ; :: thesis: t . i in p . (k + 1)
hence t . i in p . (k + 1) by A159, A161; :: thesis: verum
end;
suppose A172: i <= k ; :: thesis: t . i in p . (k + 1)
( 1 <= k + 1 & k + 1 <= len the Enumeration of A ) by A166, A164, A169, A170, XXREAL_0:2;
then A173: k + 1 in dom p by A35, FINSEQ_1:1;
A174: k < len the Enumeration of A by A164, A171, XXREAL_0:2;
A175: 1 <= k by A166, A172, XXREAL_0:2;
then k in dom p by A35, A174, FINSEQ_1:1;
then A176: p . k = p /. k by PARTFUN1:def 6;
S1[k,p /. k,p /. (k + 1)] by A31, A175, A174;
then p . (k + 1) = { g where g is Subset of ((TOP-REAL n) | C) : ( g in G & ( g c= f . (k + 1) or g in p . k ) ) } by A173, A176, PARTFUN1:def 6;
hence t . i in p . (k + 1) by A165, A168, A170, A172, NAT_1:13; :: thesis: verum
end;
end;
end;
A177: S6[ 0 ] by A165;
A178: for k being Nat holds S6[k] from NAT_1:sch 2(A177, A167);
reconsider j1 = j - 1 as Nat by A163;
assume A179: t . i = t . j ; :: thesis: contradiction
A180: j1 + 1 = j ;
then A181: j1 < j by NAT_1:13;
A182: j <> 1 by A159, A161, A163, FINSEQ_1:1;
i <= j1 by A163, A180, NAT_1:13;
then t . i in p . j1 by A181, A178;
hence contradiction by A159, A162, A179, A182; :: thesis: verum
end;
now :: thesis: for x1, x2 being object st x1 in dom t & x2 in dom t & t . x1 = t . x2 holds
not x1 <> x2
let x1, x2 be object ; :: thesis: ( x1 in dom t & x2 in dom t & t . x1 = t . x2 implies not x1 <> x2 )
assume A183: ( x1 in dom t & x2 in dom t ) ; :: thesis: ( t . x1 = t . x2 implies not x1 <> x2 )
then reconsider i1 = x1, i2 = x2 as Nat ;
assume A184: t . x1 = t . x2 ; :: thesis: not x1 <> x2
assume x1 <> x2 ; :: thesis: contradiction
then ( i1 > i2 or i1 < i2 ) by XXREAL_0:1;
hence contradiction by A160, A183, A184; :: thesis: verum
end;
then t is one-to-one by FUNCT_1:def 4;
then A185: card (rng t) = len t by FINSEQ_4:62
.= len the Enumeration of A by A159, FINSEQ_1:def 3
.= n + 1 by A1, A9, FINSEQ_4:62 ;
then A186: not rng t is empty ;
A187: now :: thesis: for x being set st x in rng t holds
I in x
let x be set ; :: thesis: ( x in rng t implies I in x )
assume x in rng t ; :: thesis: I in x
then consider i being object such that
A188: ( i in dom t & t . i = x ) by FUNCT_1:def 3;
thus I in x by A159, A188; :: thesis: verum
end;
A189: rng t c= G
proof
let y be object ; :: according to TARSKI:def 3 :: thesis: ( not y in rng t or y in G )
assume y in rng t ; :: thesis: y in G
then consider x being object such that
A190: ( x in dom t & t . x = y ) by FUNCT_1:def 3;
thus y in G by A159, A190; :: thesis: verum
end;
n < card (rng t) by A185, NAT_1:13;
then card (Segm n) in card (Segm (card (rng t))) by NAT_1:41;
then n1 + 1 in card (rng t) ;
then meet (rng t) is empty by A26, A189, TOPDIM_2:2;
hence contradiction by A186, A187, SETFAM_1:def 1; :: thesis: verum
end;
( ind (conv A) <= ind (TOP-REAL n) & ind (TOP-REAL n) <= n ) by TOPDIM_1:20, TOPDIM_2:21;
then ind (conv A) <= n by XXREAL_0:2;
hence ind (conv A) = n by A2, XXREAL_0:1; :: thesis: verum