let M be non limit_cardinal Aleph; :: thesis: for I being Ideal of M st I is_complete_with M & Frechet_Ideal M c= I holds
ex S being Subset-Family of M st
( card S = M & ( for X1 being set st X1 in S holds
not X1 in I ) & ( for X1, X2 being set st X1 in S & X2 in S & X1 <> X2 holds
X1 misses X2 ) )
set N = predecessor M;
A1:
M = nextcard (predecessor M)
by Def17;
let I be Ideal of M; :: thesis: ( I is_complete_with M & Frechet_Ideal M c= I implies ex S being Subset-Family of M st
( card S = M & ( for X1 being set st X1 in S holds
not X1 in I ) & ( for X1, X2 being set st X1 in S & X2 in S & X1 <> X2 holds
X1 misses X2 ) ) )
assume that
A2:
I is_complete_with M
and
A3:
Frechet_Ideal M c= I
; :: thesis: ex S being Subset-Family of M st
( card S = M & ( for X1 being set st X1 in S holds
not X1 in I ) & ( for X1, X2 being set st X1 in S & X2 in S & X1 <> X2 holds
X1 misses X2 ) )
consider T being Inf_Matrix of (predecessor M),M,(bool M) such that
A4:
T is_Ulam_Matrix_of M
by Th34;
A5:
for K1 being Element of M holds union { (T . N1,K1) where N1 is Element of predecessor M : N1 in predecessor M } in dual I
proof
let K1 be
Element of
M;
:: thesis: union { (T . N1,K1) where N1 is Element of predecessor M : N1 in predecessor M } in dual I
defpred S1[
set ,
set ]
means ( $2
= K1 & $1
in predecessor M );
defpred S2[
set ,
set ]
means $1
in predecessor M;
deffunc H1(
Element of
predecessor M,
Element of
M)
-> Element of
bool M =
T . $1,$2;
A6:
{ H1(N1,K2) where N1 is Element of predecessor M, K2 is Element of M : S1[N1,K2] } is
Subset-Family of
M
from DOMAIN_1:sch 9();
{ H1(N1,K2) where N1 is Element of predecessor M, K2 is Element of M : ( K2 = K1 & S2[N1,K2] ) } = { H1(N2,K1) where N2 is Element of predecessor M : S2[N2,K1] }
from FRAENKEL:sch 20();
then reconsider C =
{ (T . N1,K1) where N1 is Element of predecessor M : N1 in predecessor M } as
Subset-Family of
M by A6;
A7:
card (M \ (union { (T . N1,K1) where N1 is Element of predecessor M : N1 in predecessor M } )) c= predecessor M
by A4, Def18;
assume
not
union { (T . N1,K1) where N1 is Element of predecessor M : N1 in predecessor M } in dual I
;
:: thesis: contradiction
then
not
(union C) ` in Frechet_Ideal M
by A3, SETFAM_1:def 8;
then
not
card (M \ (union { (T . N1,K1) where N1 is Element of predecessor M : N1 in predecessor M } )) in card M
by Th19;
then
not
card (M \ (union { (T . N1,K1) where N1 is Element of predecessor M : N1 in predecessor M } )) in nextcard (predecessor M)
by A1, CARD_1:def 5;
hence
contradiction
by A7, CARD_3:108;
:: thesis: verum
end;
defpred S1[ set , set ] means not T . $2,$1 in I;
A8:
for K1 being Element of M ex N2 being Element of predecessor M st S1[K1,N2]
proof
let K1 be
Element of
M;
:: thesis: ex N2 being Element of predecessor M st S1[K1,N2]
assume A9:
for
N2 being
Element of
predecessor M holds
T . N2,
K1 in I
;
:: thesis: contradiction
A10:
{ (T . N1,K1) where N1 is Element of predecessor M : N1 in predecessor M } c= I
A13:
not
{ (T . N1,K1) where N1 is Element of predecessor M : N1 in predecessor M } is
empty
A14:
predecessor M in M
by A1, CARD_1:32;
deffunc H1(
set )
-> set =
T . $1;
A15:
card { H1(X) where X is Element of [:(predecessor M),M:] : X in [:(predecessor M),{K1}:] } c= card [:(predecessor M),{K1}:]
from TREES_2:sch 2();
{ (T . N1,K1) where N1 is Element of predecessor M : N1 in predecessor M } c= { (T . X) where X is Element of [:(predecessor M),M:] : X in [:(predecessor M),{K1}:] }
proof
let Y be
set ;
:: according to TARSKI:def 3 :: thesis: ( not Y in { (T . N1,K1) where N1 is Element of predecessor M : N1 in predecessor M } or Y in { (T . X) where X is Element of [:(predecessor M),M:] : X in [:(predecessor M),{K1}:] } )
assume A16:
Y in { (T . N1,K1) where N1 is Element of predecessor M : N1 in predecessor M }
;
:: thesis: Y in { (T . X) where X is Element of [:(predecessor M),M:] : X in [:(predecessor M),{K1}:] }
consider N1 being
Element of
predecessor M such that A17:
(
Y = T . N1,
K1 &
N1 in predecessor M )
by A16;
(
[N1,K1] is
Element of
[:(predecessor M),M:] &
[N1,K1] in [:(predecessor M),{K1}:] )
by ZFMISC_1:106, ZFMISC_1:129;
hence
Y in { (T . X) where X is Element of [:(predecessor M),M:] : X in [:(predecessor M),{K1}:] }
by A17;
:: thesis: verum
end;
then A18:
card { (T . N1,K1) where N1 is Element of predecessor M : N1 in predecessor M } c= card { (T . X) where X is Element of [:(predecessor M),M:] : X in [:(predecessor M),{K1}:] }
by CARD_1:27;
card [:(predecessor M),{K1}:] = card (predecessor M)
by CARD_2:13;
then
card [:(predecessor M),{K1}:] = predecessor M
by CARD_1:def 5;
then
card { (T . N1,K1) where N1 is Element of predecessor M : N1 in predecessor M } in M
by A14, A15, A18, ORDINAL1:22, XBOOLE_1:1;
then
union { (T . N1,K1) where N1 is Element of predecessor M : N1 in predecessor M } in I
by A2, A10, A13, Def4;
hence
contradiction
by A5, Th10;
:: thesis: verum
end;
consider h being Function of M,(predecessor M) such that
A20:
for K1 being Element of M holds S1[K1,h . K1]
from FUNCT_2:sch 3(A8);
ex N2 being Element of predecessor M st card (h " {N2}) = M
then consider N2 being Element of predecessor M such that
A27:
card (h " {N2}) = M
;
{ (T . N2,K2) where K2 is Element of M : h . K2 = N2 } c= bool M
then reconsider S = { (T . N2,K2) where K2 is Element of M : h . K2 = N2 } as Subset-Family of M ;
take
S
; :: thesis: ( card S = M & ( for X1 being set st X1 in S holds
not X1 in I ) & ( for X1, X2 being set st X1 in S & X2 in S & X1 <> X2 holds
X1 misses X2 ) )
A30:
for K1, K2 being Element of M st h . K1 = N2 & K1 <> K2 holds
T . N2,K1 <> T . N2,K2
proof
let K1,
K2 be
Element of
M;
:: thesis: ( h . K1 = N2 & K1 <> K2 implies T . N2,K1 <> T . N2,K2 )
assume A31:
(
h . K1 = N2 &
K1 <> K2 )
;
:: thesis: T . N2,K1 <> T . N2,K2
assume
T . N2,
K1 = T . N2,
K2
;
:: thesis: contradiction
then
(T . N2,K1) /\ (T . N2,K2) <> {}
by A20, A31, Th11;
hence
contradiction
by A4, A31, Def18;
:: thesis: verum
end;
h " {N2},M are_equipotent
by A27, CARD_1:def 5;
then consider f being Function such that
A32:
( f is one-to-one & dom f = M & rng f = h " {N2} )
by WELLORD2:def 4;
A33:
for X being set st X in dom f holds
h . (f . X) = N2
dom T = [:(predecessor M),M:]
by FUNCT_2:def 1;
then consider G being Function such that
(curry T) . N2 = G
and
A35:
( dom G = M & rng G c= rng T )
and
A36:
for y being set st y in M holds
G . y = T . N2,y
by FUNCT_5:36;
A37:
dom (G * f) = M
by A32, A35, RELAT_1:46;
A38:
dom (G * f) = dom f
by A32, A35, RELAT_1:46;
A39:
rng (G * f) = S
proof
thus
rng (G * f) c= S
:: according to XBOOLE_0:def 10 :: thesis: S c= rng (G * f)
thus
S c= rng (G * f)
:: thesis: verumproof
let X be
set ;
:: according to TARSKI:def 3 :: thesis: ( not X in S or X in rng (G * f) )
assume A43:
X in S
;
:: thesis: X in rng (G * f)
consider K2 being
Element of
M such that A44:
(
X = T . N2,
K2 &
h . K2 = N2 )
by A43;
A45:
h . K2 in {N2}
by A44, TARSKI:def 1;
K2 in M
;
then
K2 in dom h
by FUNCT_2:def 1;
then
K2 in h " {N2}
by A45, FUNCT_1:def 13;
then consider K3 being
set such that A46:
(
K3 in dom f &
f . K3 = K2 )
by A32, FUNCT_1:def 5;
X = G . (f . K3)
by A36, A44, A46;
then
X = (G * f) . K3
by A38, A46, FUNCT_1:22;
hence
X in rng (G * f)
by A38, A46, FUNCT_1:def 5;
:: thesis: verum
end;
end;
G * f is one-to-one
proof
let K1,
K2 be
set ;
:: according to FUNCT_1:def 8 :: thesis: ( not K1 in proj1 (G * f) or not K2 in proj1 (G * f) or not (G * f) . K1 = (G * f) . K2 or K1 = K2 )
assume that A47:
(
K1 in dom (G * f) &
K2 in dom (G * f) )
and A48:
(G * f) . K1 = (G * f) . K2
;
:: thesis: K1 = K2
A49:
(
f . K1 in rng f &
f . K2 in rng f )
by A38, A47, FUNCT_1:def 5;
assume
K1 <> K2
;
:: thesis: contradiction
then A50:
f . K1 <> f . K2
by A32, A38, A47, FUNCT_1:def 8;
reconsider K3 =
f . K1 as
Element of
M by A32, A49;
A51:
h . K3 = N2
by A33, A38, A47;
reconsider K4 =
f . K2 as
Element of
M by A32, A49;
A52:
T . N2,
K3 <> T . N2,
K4
by A30, A50, A51;
A53:
(G * f) . K1 =
G . (f . K1)
by A47, FUNCT_1:22
.=
T . N2,
(f . K1)
by A32, A36, A49
;
(G * f) . K2 =
G . (f . K2)
by A47, FUNCT_1:22
.=
T . N2,
(f . K2)
by A32, A36, A49
;
hence
contradiction
by A48, A52, A53;
:: thesis: verum
end;
then
S,M are_equipotent
by A37, A39, WELLORD2:def 4;
hence
card S = M
by CARD_1:def 5; :: thesis: ( ( for X1 being set st X1 in S holds
not X1 in I ) & ( for X1, X2 being set st X1 in S & X2 in S & X1 <> X2 holds
X1 misses X2 ) )
thus
for X1 being set st X1 in S holds
not X1 in I
:: thesis: for X1, X2 being set st X1 in S & X2 in S & X1 <> X2 holds
X1 misses X2
thus
for X1, X2 being set st X1 in S & X2 in S & X1 <> X2 holds
X1 misses X2
:: thesis: verumproof
let X1,
X2 be
set ;
:: thesis: ( X1 in S & X2 in S & X1 <> X2 implies X1 misses X2 )
assume A57:
(
X1 in S &
X2 in S &
X1 <> X2 )
;
:: thesis: X1 misses X2
consider K1 being
Element of
M such that A58:
T . N2,
K1 = X1
and
h . K1 = N2
by A57;
consider K2 being
Element of
M such that A59:
T . N2,
K2 = X2
and
h . K2 = N2
by A57;
(T . N2,K1) /\ (T . N2,K2) = {}
by A4, A57, A58, A59, Def18;
hence
X1 misses X2
by A58, A59, XBOOLE_0:def 7;
:: thesis: verum
end;