let n, k be Nat; for A, B being object
for f being FinSequence st f is A,n,B,k -dominated-election holds
f . 1 = A
let A, B be object ; for f being FinSequence st f is A,n,B,k -dominated-election holds
f . 1 = A
let f be FinSequence; ( f is A,n,B,k -dominated-election implies f . 1 = A )
set f1 = f | 1;
assume A1:
f is A,n,B,k -dominated-election
; f . 1 = A
then
n > k
by Th14;
then
len f >= 1 + 0
by A1, NAT_1:13;
then A2:
len (f | 1) = 1
by FINSEQ_1:59;
card ((f | 1) " {A}) > card ((f | 1) " {B})
by A1;
then A3:
not (f | 1) " {A} is empty
;
dom (f | 1) = Seg 1
by FINSEQ_1:def 3, A2;
then A4:
(f | 1) " {A} = {1}
by RELAT_1:132, FINSEQ_1:2, A3, ZFMISC_1:33;
1 in {1}
by FINSEQ_1:2;
then
(f | 1) . 1 in {A}
by A4, FUNCT_1:def 7;
then
A = (f | 1) . 1
by TARSKI:def 1;
hence
f . 1 = A
by FINSEQ_3:112; verum