let X be set ; for S being non empty Subset-Family of X st ( for A, B being Element of S ex P being finite Subset of S st P is a_partition of A /\ B ) & ( for C, D being Element of S st D c= C holds
ex P being finite Subset of S st P is a_partition of C \ D ) holds
for A being Element of S
for Q being finite Subset of S st not A is empty & union Q c= A & Q is a_partition of union Q holds
ex R being finite Subset of S st
( union R misses union Q & Q \/ R is a_partition of A )
let S be non empty Subset-Family of X; ( ( for A, B being Element of S ex P being finite Subset of S st P is a_partition of A /\ B ) & ( for C, D being Element of S st D c= C holds
ex P being finite Subset of S st P is a_partition of C \ D ) implies for A being Element of S
for Q being finite Subset of S st not A is empty & union Q c= A & Q is a_partition of union Q holds
ex R being finite Subset of S st
( union R misses union Q & Q \/ R is a_partition of A ) )
assume A1:
for A, B being Element of S ex P being finite Subset of S st P is a_partition of A /\ B
; ( ex C, D being Element of S st
( D c= C & ( for P being finite Subset of S holds P is not a_partition of C \ D ) ) or for A being Element of S
for Q being finite Subset of S st not A is empty & union Q c= A & Q is a_partition of union Q holds
ex R being finite Subset of S st
( union R misses union Q & Q \/ R is a_partition of A ) )
assume A2:
for C, D being Element of S st D c= C holds
ex P being finite Subset of S st P is a_partition of C \ D
; for A being Element of S
for Q being finite Subset of S st not A is empty & union Q c= A & Q is a_partition of union Q holds
ex R being finite Subset of S st
( union R misses union Q & Q \/ R is a_partition of A )
let A be Element of S; for Q being finite Subset of S st not A is empty & union Q c= A & Q is a_partition of union Q holds
ex R being finite Subset of S st
( union R misses union Q & Q \/ R is a_partition of A )
let Q be finite Subset of S; ( not A is empty & union Q c= A & Q is a_partition of union Q implies ex R being finite Subset of S st
( union R misses union Q & Q \/ R is a_partition of A ) )
assume that
A3:
not A is empty
and
A4:
union Q c= A
and
A5:
Q is a_partition of union Q
; ex R being finite Subset of S st
( union R misses union Q & Q \/ R is a_partition of A )
consider qq being FinSequence such that
A6:
Q = rng qq
by FINSEQ_1:52;
A7:
for i being set st i in dom qq holds
qq . i <> {}
per cases
( qq = {} or qq <> {} )
;
suppose A13:
qq <> {}
;
ex R being finite Subset of S st
( union R misses union Q & Q \/ R is a_partition of A )defpred S1[
Nat]
means for
n being
Nat st $1
= n & 1
<= n &
n <= len qq holds
ex
R being
finite Subset of
S st
(
union R misses union (rng (qq | (Seg n))) &
(rng (qq | (Seg n))) \/ R is
a_partition of
A );
A14:
S1[1]
A23:
for
j being
Nat st 1
<= j &
S1[
j] holds
S1[
j + 1]
proof
let j be
Nat;
( 1 <= j & S1[j] implies S1[j + 1] )
assume that A24:
1
<= j
and A25:
S1[
j]
;
S1[j + 1]
for
n being
Nat st
j + 1
= n & 1
<= n &
n <= len qq holds
ex
R being
finite Subset of
S st
(
union R misses union (rng (qq | (Seg n))) &
(rng (qq | (Seg n))) \/ R is
a_partition of
A )
proof
let n be
Nat;
( j + 1 = n & 1 <= n & n <= len qq implies ex R being finite Subset of S st
( union R misses union (rng (qq | (Seg n))) & (rng (qq | (Seg n))) \/ R is a_partition of A ) )
assume that A26:
j + 1
= n
and A27:
1
<= n
and A28:
n <= len qq
;
ex R being finite Subset of S st
( union R misses union (rng (qq | (Seg n))) & (rng (qq | (Seg n))) \/ R is a_partition of A )
per cases
( j <= len qq or not j <= len qq )
;
suppose
j <= len qq
;
ex R being finite Subset of S st
( union R misses union (rng (qq | (Seg n))) & (rng (qq | (Seg n))) \/ R is a_partition of A )then consider R1 being
finite Subset of
S such that A29:
union R1 misses union (rng (qq | (Seg j)))
and A30:
(rng (qq | (Seg j))) \/ R1 is
a_partition of
A
by A24, A25;
A31:
n in Seg (len qq)
by A27, A28;
then A32:
j + 1
in dom qq
by A26, FINSEQ_1:def 3;
Seg (j + 1) = (Seg j) \/ {(j + 1)}
by FINSEQ_1:9;
then
qq | (Seg (j + 1)) = (qq | (Seg j)) \/ (qq | {(j + 1)})
by RELAT_1:78;
then A33:
rng (qq | (Seg (j + 1))) = (rng (qq | (Seg j))) \/ (rng (qq | {(j + 1)}))
by RELAT_1:12;
then A34:
rng (qq | (Seg (j + 1))) = (rng (qq | (Seg j))) \/ {(qq . (j + 1))}
by A32, FUNCT_1:98;
per cases
( qq . (j + 1) in rng (qq | (Seg j)) or not qq . (j + 1) in rng (qq | (Seg j)) )
;
suppose A35:
not
qq . (j + 1) in rng (qq | (Seg j))
;
ex R being finite Subset of S st
( union R misses union (rng (qq | (Seg n))) & (rng (qq | (Seg n))) \/ R is a_partition of A )A36:
qq . (j + 1) misses union (rng (qq | (Seg j)))
proof
assume
not
(qq . (j + 1)) /\ (union (rng (qq | (Seg j)))) = {}
;
XBOOLE_0:def 7 contradiction
then consider x0 being
object such that A37:
x0 in (qq . (j + 1)) /\ (union (rng (qq | (Seg j))))
by XBOOLE_0:def 1;
(
x0 in qq . (j + 1) &
x0 in Union (qq | (Seg j)) )
by A37, XBOOLE_0:def 4;
then consider y0 being
set such that A38:
(
x0 in y0 &
y0 in rng (qq | (Seg j)) )
by TARSKI:def 4;
consider j0 being
object such that A39:
j0 in dom (qq | (Seg j))
and A40:
y0 = (qq | (Seg j)) . j0
by A38, FUNCT_1:def 3;
(
x0 in qq . j0 &
x0 in qq . (j + 1) )
by A37, XBOOLE_0:def 4, A38, A40, A39, FUNCT_1:47;
then A41:
x0 in (qq . j0) /\ (qq . (j + 1))
by XBOOLE_0:def 4;
dom (qq | (Seg j)) c= dom qq
by RELAT_1:60;
then
(
j0 in dom qq &
j + 1
in dom qq )
by A39, A31, A26, FINSEQ_1:def 3;
then
(
qq . j0 in Q &
qq . (j + 1) in Q )
by A6, FUNCT_1:def 3;
then
qq . j0 = qq . (j + 1)
by A5, A41, XBOOLE_0:def 7, EQREL_1:def 4;
hence
contradiction
by A35, A38, A40, A39, FUNCT_1:47;
verum
end; A42:
qq . (j + 1) in Q
by A32, A6, FUNCT_1:def 3;
then A43:
qq . (j + 1) c= union Q
by ZFMISC_1:74;
then A44:
qq . (j + 1) c= A
by A4, XBOOLE_1:1;
consider RA being
finite Subset of
S such that A45:
RA is
a_partition of
A \ (qq . (j + 1))
by A42, A43, A4, XBOOLE_1:1, A2;
A46:
for
x being
set st
x in [:R1,RA:] holds
ex
x1,
x2 being
set ex
px being
finite Subset of
S st
(
x = [x1,x2] &
x1 in R1 &
x2 in RA &
px is
a_partition of
x1 /\ x2 )
proof
let x be
set ;
( x in [:R1,RA:] implies ex x1, x2 being set ex px being finite Subset of S st
( x = [x1,x2] & x1 in R1 & x2 in RA & px is a_partition of x1 /\ x2 ) )
assume
x in [:R1,RA:]
;
ex x1, x2 being set ex px being finite Subset of S st
( x = [x1,x2] & x1 in R1 & x2 in RA & px is a_partition of x1 /\ x2 )
then consider x1,
x2 being
object such that A47:
(
x1 in R1 &
x2 in RA &
x = [x1,x2] )
by ZFMISC_1:def 2;
reconsider x1 =
x1,
x2 =
x2 as
set by TARSKI:1;
consider px being
finite Subset of
S such that A48:
px is
a_partition of
x1 /\ x2
by A47, A1;
thus
ex
x1,
x2 being
set ex
px being
finite Subset of
S st
(
x = [x1,x2] &
x1 in R1 &
x2 in RA &
px is
a_partition of
x1 /\ x2 )
by A47, A48;
verum
end; defpred S2[
object ,
object ]
means ( $1
in [:R1,RA:] & ex
x1,
x2 being
set ex
px being
finite Subset of
S st
( $1
= [x1,x2] &
x1 in R1 &
x2 in RA & $2
= px & $2 is
a_partition of
x1 /\ x2 ) );
set XA =
{ x where x is finite Subset of S : verum } ;
A49:
for
x being
object st
x in [:R1,RA:] holds
ex
y being
object st
(
y in { x where x is finite Subset of S : verum } &
S2[
x,
y] )
proof
let x be
object ;
( x in [:R1,RA:] implies ex y being object st
( y in { x where x is finite Subset of S : verum } & S2[x,y] ) )
assume A50:
x in [:R1,RA:]
;
ex y being object st
( y in { x where x is finite Subset of S : verum } & S2[x,y] )
then consider x1,
x2 being
set ,
px being
finite Subset of
S such that A51:
x = [x1,x2]
and A52:
(
x1 in R1 &
x2 in RA )
and A53:
px is
a_partition of
x1 /\ x2
by A46;
px in { x where x is finite Subset of S : verum }
;
hence
ex
y being
object st
(
y in { x where x is finite Subset of S : verum } &
S2[
x,
y] )
by A50, A51, A52, A53;
verum
end; consider h being
Function such that A55:
(
dom h = [:R1,RA:] &
rng h c= { x where x is finite Subset of S : verum } )
and A56:
for
x being
object st
x in [:R1,RA:] holds
S2[
x,
h . x]
from FUNCT_1:sch 6(A49);
A57:
Union h is
finite
A61:
rng h c= bool S
A65:
Union h c= S
A68:
union (Union h) misses union (rng (qq | (Seg n)))
proof
(union (Union h)) /\ (union (rng (qq | (Seg (j + 1))))) c= {}
proof
let x be
object ;
TARSKI:def 3 ( not x in (union (Union h)) /\ (union (rng (qq | (Seg (j + 1))))) or x in {} )
assume
x in (union (Union h)) /\ (union (rng (qq | (Seg (j + 1)))))
;
x in {}
then A69:
(
x in union (Union h) &
x in union (rng (qq | (Seg (j + 1)))) )
by XBOOLE_0:def 4;
then consider x0 being
set such that A70:
x in x0
and A71:
x0 in Union h
by TARSKI:def 4;
consider x1 being
set such that A72:
x in x1
and A73:
x1 in rng (qq | (Seg (j + 1)))
by A69, TARSKI:def 4;
x0 /\ x1 = {}
proof
x0 /\ x1 c= {}
proof
let u be
object ;
TARSKI:def 3 ( not u in x0 /\ x1 or u in {} )
assume A74:
u in x0 /\ x1
;
u in {}
then A75:
(
u in x0 &
u in x1 )
by XBOOLE_0:def 4;
consider x0a being
set such that A76:
x0 in x0a
and A77:
x0a in rng h
by A71, TARSKI:def 4;
consider t being
object such that A78:
t in dom h
and A79:
h . t = x0a
by A77, FUNCT_1:def 3;
consider ax1,
ax2 being
set ,
apx being
finite Subset of
S such that
t = [ax1,ax2]
and A80:
(
ax1 in R1 &
ax2 in RA )
and A81:
x0a = apx
and A82:
x0a is
a_partition of
ax1 /\ ax2
by A78, A79, A55, A56;
A83:
(
u in x0 &
x0 in apx )
by A74, XBOOLE_0:def 4, A76, A81;
(
u in ax1 &
ax1 in R1 )
by A83, A82, A81, A80, XBOOLE_0:def 4;
then
u in union R1
by TARSKI:def 4;
then A85:
not
u in union (rng (qq | (Seg j)))
by A29, XBOOLE_0:def 4;
(
u in ax2 &
ax2 in RA )
by A83, A82, A81, XBOOLE_0:def 4, A80;
then A85a:
not
u in qq . (j + 1)
by A45, XBOOLE_0:def 5;
union (rng (qq | (Seg (j + 1)))) = union ((rng (qq | (Seg j))) \/ {(qq . (j + 1))})
by A33, A32, FUNCT_1:98;
then
union (rng (qq | (Seg (j + 1)))) = (union (rng (qq | (Seg j)))) \/ (union {(qq . (j + 1))})
by ZFMISC_1:78;
then
not
u in union (rng (qq | (Seg (j + 1))))
by A85, XBOOLE_0:def 3, A85a;
hence
u in {}
by A75, A73, TARSKI:def 4;
verum
end;
hence
x0 /\ x1 = {}
;
verum
end;
hence
x in {}
by A70, A72, XBOOLE_0:def 4;
verum
end;
hence
union (Union h) misses union (rng (qq | (Seg n)))
by A26;
verum
end;
(rng (qq | (Seg n))) \/ (Union h) is
a_partition of
A
proof
A87:
(rng (qq | (Seg n))) \/ (Union h) c= bool A
proof
let x be
object ;
TARSKI:def 3 ( not x in (rng (qq | (Seg n))) \/ (Union h) or x in bool A )
assume A88:
x in (rng (qq | (Seg n))) \/ (Union h)
;
x in bool A
A89:
(
x in rng (qq | (Seg n)) implies
x in bool A )
(
x in Union h implies
x in bool A )
proof
assume
x in Union h
;
x in bool A
then consider y being
set such that A91:
x in y
and A92:
y in rng h
by TARSKI:def 4;
consider z being
object such that A93:
z in dom h
and A94:
y = h . z
by A92, FUNCT_1:def 3;
consider x1,
x2 being
set ,
px being
finite Subset of
S such that
z = [x1,x2]
and A95:
(
x1 in R1 &
x2 in RA )
and
y = px
and A96:
y is
a_partition of
x1 /\ x2
by A55, A56, A93, A94;
A97:
x1 /\ x2 c= x2
by XBOOLE_1:17;
A \ (qq . (j + 1)) c= A
by XBOOLE_1:36;
then
x2 c= A
by A45, A95, XBOOLE_1:1;
then
x1 /\ x2 c= A
by A97, XBOOLE_1:1;
then
bool (x1 /\ x2) c= bool A
by ZFMISC_1:67;
then
y c= bool A
by A96, XBOOLE_1:1;
hence
x in bool A
by A91;
verum
end;
hence
x in bool A
by A88, A89, XBOOLE_0:def 3;
verum
end;
A98:
union ((rng (qq | (Seg n))) \/ (Union h)) = A
proof
A99:
union ((rng (qq | (Seg n))) \/ (Union h)) c= A
A c= union ((rng (qq | (Seg n))) \/ (Union h))
proof
let x be
object ;
TARSKI:def 3 ( not x in A or x in union ((rng (qq | (Seg n))) \/ (Union h)) )
assume
x in A
;
x in union ((rng (qq | (Seg n))) \/ (Union h))
then
x in union ((rng (qq | (Seg j))) \/ R1)
by A30, EQREL_1:def 4;
then A102:
x in (union (rng (qq | (Seg j)))) \/ (union R1)
by ZFMISC_1:78;
A103:
(
x in union (rng (qq | (Seg j))) implies
x in union (rng (qq | (Seg (j + 1)))) )
( not
x in union R1 or
x in union (Union h) or
x in union (rng (qq | (Seg (j + 1)))) )
proof
assume A105:
x in union R1
;
( x in union (Union h) or x in union (rng (qq | (Seg (j + 1)))) )
union R1 c= (union R1) \/ (union (rng (qq | (Seg j))))
by XBOOLE_1:7;
then
union R1 c= union (R1 \/ (rng (qq | (Seg j))))
by ZFMISC_1:78;
then A106:
union R1 c= A
by A30, EQREL_1:def 4;
A107:
(
x in qq . (j + 1) implies
x in union (rng (qq | (Seg (j + 1)))) )
( not
x in qq . (j + 1) implies
x in union (Union h) )
proof
assume
not
x in qq . (j + 1)
;
x in union (Union h)
then
x in A \ (qq . (j + 1))
by A105, A106, XBOOLE_0:def 5;
then
x in union RA
by A45, EQREL_1:def 4;
then consider y being
set such that A109:
x in y
and A110:
y in RA
by TARSKI:def 4;
consider z being
set such that A111:
x in z
and A112:
z in R1
by A105, TARSKI:def 4;
consider t being
set such that A113:
t = [z,y]
;
A114:
[z,y] in [:R1,RA:]
by A110, A112, ZFMISC_1:def 2;
A115:
[z,y] in dom h
by A110, A112, ZFMISC_1:def 2, A55;
consider x1,
x2 being
set ,
px being
finite Subset of
S such that A116:
t = [x1,x2]
and
(
x1 in R1 &
x2 in RA )
and
h . t = px
and A117:
h . t is
a_partition of
x1 /\ x2
by A113, A56, A114;
A118:
(
z = x1 &
y = x2 )
by A113, A116, XTUPLE_0:1;
x in z /\ y
by A109, A111, XBOOLE_0:def 4;
then A119:
x in union (h . t)
by A117, A118, EQREL_1:def 4;
h . t in rng h
by A113, A115, FUNCT_1:def 3;
then
union (h . t) c= union (union (rng h))
by ZFMISC_1:74, ZFMISC_1:77;
hence
x in union (Union h)
by A119;
verum
end;
hence
(
x in union (Union h) or
x in union (rng (qq | (Seg (j + 1)))) )
by A107;
verum
end;
then
x in (union (rng (qq | (Seg (j + 1))))) \/ (union (Union h))
by A102, A103, XBOOLE_0:def 3;
hence
x in union ((rng (qq | (Seg n))) \/ (Union h))
by ZFMISC_1:78, A26;
verum
end;
hence
union ((rng (qq | (Seg n))) \/ (Union h)) = A
by A99;
verum
end;
for
a being
Subset of
A st
a in (rng (qq | (Seg n))) \/ (Union h) holds
(
a <> {} & ( for
b being
Subset of
A holds
( not
b in (rng (qq | (Seg n))) \/ (Union h) or
a = b or
a misses b ) ) )
proof
let a be
Subset of
A;
( a in (rng (qq | (Seg n))) \/ (Union h) implies ( a <> {} & ( for b being Subset of A holds
( not b in (rng (qq | (Seg n))) \/ (Union h) or a = b or a misses b ) ) ) )
assume A120:
a in (rng (qq | (Seg n))) \/ (Union h)
;
( a <> {} & ( for b being Subset of A holds
( not b in (rng (qq | (Seg n))) \/ (Union h) or a = b or a misses b ) ) )
A121:
(
a in (rng (qq | (Seg j))) \/ {(qq . (j + 1))} or
a in Union h )
by A34, A120, A26, XBOOLE_0:def 3;
A122:
a <> {}
for
b being
Subset of
A holds
( not
b in (rng (qq | (Seg n))) \/ (Union h) or
a = b or
a misses b )
proof
let b be
Subset of
A;
( not b in (rng (qq | (Seg n))) \/ (Union h) or a = b or a misses b )
assume
b in (rng (qq | (Seg n))) \/ (Union h)
;
( a = b or a misses b )
then
(
b in rng (qq | (Seg (j + 1))) or
b in Union h )
by A26, XBOOLE_0:def 3;
then A132:
(
b in (rng (qq | (Seg j))) \/ {(qq . (j + 1))} or
b in Union h )
by A33, A32, FUNCT_1:98;
A133:
( not
b in rng (qq | (Seg j)) or
a = b or
a misses b )
A139:
( not
b in {(qq . (j + 1))} or
a = b or
a misses b )
proof
assume A140:
b in {(qq . (j + 1))}
;
( a = b or a misses b )
A141:
( not
a in rng (qq | (Seg j)) or
a = b or
a misses b )
A143:
( not
a in {(qq . (j + 1))} or
a = b or
a misses b )
( not
a in Union h or
a = b or
a misses b )
proof
assume
a in Union h
;
( a = b or a misses b )
then consider a1 being
set such that A144:
a in a1
and A145:
a1 in rng h
by TARSKI:def 4;
consider t being
object such that A146:
t in dom h
and A147:
a1 = h . t
by A145, FUNCT_1:def 3;
consider x1,
x2 being
set ,
px being
finite Subset of
S such that
t = [x1,x2]
and A148:
(
x1 in R1 &
x2 in RA )
and
a1 = px
and A149:
a1 is
a_partition of
x1 /\ x2
by A146, A147, A55, A56;
x1 /\ x2 c= x2
by XBOOLE_1:17;
then
x1 /\ x2 c= A \ (qq . (j + 1))
by A45, A148, XBOOLE_1:1;
then A150:
bool (x1 /\ x2) c= bool (A \ (qq . (j + 1)))
by ZFMISC_1:67;
A151:
a1 c= bool (A \ (qq . (j + 1)))
by A149, A150, XBOOLE_1:1;
b = qq . (j + 1)
by A140, TARSKI:def 1;
hence
(
a = b or
a misses b )
by A151, A144, XBOOLE_1:63, XBOOLE_1:79;
verum
end;
hence
(
a = b or
a misses b )
by A121, XBOOLE_0:def 3, A141, A143;
verum
end;
( not
b in Union h or
a = b or
a misses b )
proof
assume A152:
b in Union h
;
( a = b or a misses b )
A153:
( not
a in rng (qq | (Seg j)) or
a = b or
a misses b )
A156:
( not
a in {(qq . (j + 1))} or
a = b or
a misses b )
proof
assume
a in {(qq . (j + 1))}
;
( a = b or a misses b )
then A157:
a = qq . (j + 1)
by TARSKI:def 1;
consider b1 being
set such that A158:
b in b1
and A159:
b1 in rng h
by A152, TARSKI:def 4;
consider tb being
object such that A160:
tb in dom h
and A161:
b1 = h . tb
by A159, FUNCT_1:def 3;
consider bx1,
bx2 being
set ,
bpx being
finite Subset of
S such that
tb = [bx1,bx2]
and A162:
(
bx1 in R1 &
bx2 in RA )
and
b1 = bpx
and A163:
b1 is
a_partition of
bx1 /\ bx2
by A160, A161, A55, A56;
A164:
bool (bx1 /\ bx2) c= bool bx2
by XBOOLE_1:17, ZFMISC_1:67;
b1 c= bool bx2
by A163, A164, XBOOLE_1:1;
then
b c= A \ (qq . (j + 1))
by A45, A162, A158, XBOOLE_1:1;
hence
(
a = b or
a misses b )
by XBOOLE_1:79, A157, XBOOLE_1:63;
verum
end;
( not
a in Union h or
a = b or
a misses b )
proof
assume
a in Union h
;
( a = b or a misses b )
then consider a1 being
set such that A166:
a in a1
and A167:
a1 in rng h
by TARSKI:def 4;
consider t being
object such that A168:
t in dom h
and A169:
a1 = h . t
by A167, FUNCT_1:def 3;
consider x1,
x2 being
set ,
px being
finite Subset of
S such that A170:
t = [x1,x2]
and A171:
(
x1 in R1 &
x2 in RA )
and
a1 = px
and A172:
a1 is
a_partition of
x1 /\ x2
by A168, A169, A55, A56;
consider b1 being
set such that A173:
b in b1
and A174:
b1 in rng h
by A152, TARSKI:def 4;
consider tb being
object such that A175:
tb in dom h
and A176:
b1 = h . tb
by A174, FUNCT_1:def 3;
consider bx1,
bx2 being
set ,
bpx being
finite Subset of
S such that A177:
tb = [bx1,bx2]
and A178:
(
bx1 in R1 &
bx2 in RA )
and
b1 = bpx
and A179:
b1 is
a_partition of
bx1 /\ bx2
by A175, A176, A55, A56;
A180:
( not
x1 = bx1 & not
x2 = bx2 & not
a = b implies
a misses b )
proof
assume A181:
( not
x1 = bx1 & not
x2 = bx2 )
;
( a = b or a misses b )
A182:
(
x1 in (rng (qq | (Seg j))) \/ R1 &
bx1 in (rng (qq | (Seg j))) \/ R1 )
by A171, A178, XBOOLE_1:7, TARSKI:def 3;
A183:
(
bool (x1 /\ x2) c= bool x1 &
bool (bx1 /\ bx2) c= bool bx1 )
by XBOOLE_1:17, ZFMISC_1:67;
(
a1 c= bool x1 &
b1 c= bool bx1 )
by A172, A179, A183, XBOOLE_1:1;
hence
(
a = b or
a misses b )
by A182, A181, A30, EQREL_1:def 4, A166, A173, XBOOLE_1:64;
verum
end;
A184:
(
x1 = bx1 & not
x2 = bx2 & not
a = b implies
a misses b )
proof
assume A185:
(
x1 = bx1 & not
x2 = bx2 )
;
( a = b or a misses b )
A186:
(
bool (x1 /\ x2) c= bool x2 &
bool (bx1 /\ bx2) c= bool bx2 )
by XBOOLE_1:17, ZFMISC_1:67;
(
a1 c= bool x2 &
b1 c= bool bx2 )
by A172, A179, A186, XBOOLE_1:1;
hence
(
a = b or
a misses b )
by A166, A173, A185, A171, A178, A45, EQREL_1:def 4, XBOOLE_1:64;
verum
end;
( not
x1 = bx1 &
x2 = bx2 & not
a = b implies
a misses b )
proof
assume A187:
( not
x1 = bx1 &
x2 = bx2 )
;
( a = b or a misses b )
A188:
(
x1 in (rng (qq | (Seg j))) \/ R1 &
bx1 in (rng (qq | (Seg j))) \/ R1 )
by A171, A178, XBOOLE_1:7, TARSKI:def 3;
A189:
(
bool (x1 /\ x2) c= bool x1 &
bool (bx1 /\ bx2) c= bool bx1 )
by XBOOLE_1:17, ZFMISC_1:67;
(
a1 c= bool x1 &
b1 c= bool bx1 )
by A172, A179, A189, XBOOLE_1:1;
hence
(
a = b or
a misses b )
by A166, A173, XBOOLE_1:64, A188, A187, A30, EQREL_1:def 4;
verum
end;
hence
(
a = b or
a misses b )
by A169, A176, A170, A177, A166, A173, A172, EQREL_1:def 4, A180, A184;
verum
end;
hence
(
a = b or
a misses b )
by A121, XBOOLE_0:def 3, A153, A156;
verum
end;
hence
(
a = b or
a misses b )
by A132, XBOOLE_0:def 3, A133, A139;
verum
end;
hence
(
a <> {} & ( for
b being
Subset of
A holds
( not
b in (rng (qq | (Seg n))) \/ (Union h) or
a = b or
a misses b ) ) )
by A122;
verum
end;
hence
(rng (qq | (Seg n))) \/ (Union h) is
a_partition of
A
by A87, A98, EQREL_1:def 4;
verum
end; hence
ex
R being
finite Subset of
S st
(
union R misses union (rng (qq | (Seg n))) &
(rng (qq | (Seg n))) \/ R is
a_partition of
A )
by A65, A57, A68;
verum end; end; end; end;
end;
hence
S1[
j + 1]
;
verum
end; A190:
for
i being
Nat st 1
<= i holds
S1[
i]
from NAT_1:sch 8(A14, A23);
A191:
(
len qq is
Nat & 1
<= len qq )
by A13, FINSEQ_1:20;
consider R being
finite Subset of
S such that A192:
union R misses union (rng (qq | (Seg (len qq))))
and A193:
(rng (qq | (Seg (len qq)))) \/ R is
a_partition of
A
by A190, A191;
rng (qq | (Seg (len qq))) = Q
hence
ex
R being
finite Subset of
S st
(
union R misses union Q &
Q \/ R is
a_partition of
A )
by A193, A192;
verum end; end;