let n, k, i be Nat; for A, B being object
for f being FinSequence st f is A,n,B,k -dominated-election & i < n - k holds
f ^ (i |-> B) is A,n,B,k + i -dominated-election
let A, B be object ; for f being FinSequence st f is A,n,B,k -dominated-election & i < n - k holds
f ^ (i |-> B) is A,n,B,k + i -dominated-election
let f be FinSequence; ( f is A,n,B,k -dominated-election & i < n - k implies f ^ (i |-> B) is A,n,B,k + i -dominated-election )
set iB = i |-> B;
assume that
A1:
f is A,n,B,k -dominated-election
and
A2:
i < n - k
; f ^ (i |-> B) is A,n,B,k + i -dominated-election
A3:
A <> B
by A1, Th13;
A4:
rng (i |-> B) c= {B}
by FUNCOP_1:13;
{B} c= {A,B}
by ZFMISC_1:7;
then
rng (i |-> B) c= {A,B}
by A4;
then reconsider iB = i |-> B as FinSequence of {A,B} by FINSEQ_1:def 4;
reconsider F = f as Element of (n + k) -tuples_on {A,B} by A1;
set fB = f ^ (i |-> B);
A5:
len f = n + k
by A1, CARD_1:def 7;
A6:
len (F ^ iB) = (n + k) + i
by CARD_1:def 7;
then reconsider FB = F ^ iB as Element of (n + (k + i)) -tuples_on {A,B} by FINSEQ_2:92;
A7:
not B in {A}
by A3, TARSKI:def 1;
then A8:
iB " {A} = {}
by FUNCOP_1:16;
A9:
card (FB " {A}) = (card (F " {A})) + (card (iB " {A}))
by FINSEQ_3:57;
A10:
card (F " {A}) = n
by Def1, A1;
hence
f ^ (i |-> B) in Election (A,n,B,(k + i))
by A9, A8, Def1; BALLOT_1:def 2 for i being Nat st i > 0 holds
card (((f ^ (i |-> B)) | i) " {A}) > card (((f ^ (i |-> B)) | i) " {B})
let j be Nat; ( j > 0 implies card (((f ^ (i |-> B)) | j) " {A}) > card (((f ^ (i |-> B)) | j) " {B}) )
assume A11:
j > 0
; card (((f ^ (i |-> B)) | j) " {A}) > card (((f ^ (i |-> B)) | j) " {B})
set FBj = FB | j;
A12:
card (f " {B}) = k
by A3, Th11, A1;
A13:
i + k < (n - k) + k
by A2, XREAL_1:6;
per cases
( j <= n + k or ( j > n + k & j <= (n + k) + i ) or j > (n + k) + i )
;
suppose A14:
(
j > n + k &
j <= (n + k) + i )
;
card (((f ^ (i |-> B)) | j) " {A}) > card (((f ^ (i |-> B)) | j) " {B})then reconsider j1 =
j - (n + k) as
Nat by NAT_1:21;
A15:
j1 + (n + k) <= i + (n + k)
by A14;
then A16:
j1 <= i
by XREAL_1:6;
(Seg i) /\ (Seg j1) = Seg j1
by A15, XREAL_1:6, FINSEQ_1:7;
then A17:
iB | (Seg j1) = (Seg j1) --> B
by FUNCOP_1:12;
A18:
((Seg j1) --> B) " {A} = {}
by A7, FUNCOP_1:16;
A19:
FB | j =
FB | (Seg ((len F) + j1))
by A5
.=
F ^ ((Seg j1) --> B)
by A17, FINSEQ_6:14
;
then A20:
card ((FB | j) " {A}) =
n + (card (((Seg j1) --> B) " {A}))
by A10, FINSEQ_3:57
.=
n
by A18
;
B in {B}
by TARSKI:def 1;
then
((Seg j1) --> B) " {B} = Seg j1
by FUNCOP_1:14;
then card ((FB | j) " {B}) =
k + (card (Seg j1))
by A12, A19, FINSEQ_3:57
.=
k + j1
by FINSEQ_1:57
;
then
card ((FB | j) " {B}) <= k + i
by A16, XREAL_1:6;
hence
card (((f ^ (i |-> B)) | j) " {A}) > card (((f ^ (i |-> B)) | j) " {B})
by A20, A13, XXREAL_0:2;
verum end; end;