let f1, f2 be Function of [: the carrier of Z_2,(n -tuples_on BOOLEAN):],(n -tuples_on BOOLEAN); ( ( for a being Element of BOOLEAN
for x being Element of n -tuples_on BOOLEAN
for i being set st i in Seg n holds
(f1 . (a,x)) . i = a '&' (x . i) ) & ( for a being Element of BOOLEAN
for x being Element of n -tuples_on BOOLEAN
for i being set st i in Seg n holds
(f2 . (a,x)) . i = a '&' (x . i) ) implies f1 = f2 )
assume A7:
for a being Element of BOOLEAN
for x being Element of n -tuples_on BOOLEAN
for i being set st i in Seg n holds
(f1 . (a,x)) . i = a '&' (x . i)
; ( ex a being Element of BOOLEAN ex x being Element of n -tuples_on BOOLEAN ex i being set st
( i in Seg n & not (f2 . (a,x)) . i = a '&' (x . i) ) or f1 = f2 )
assume A8:
for a being Element of BOOLEAN
for x being Element of n -tuples_on BOOLEAN
for i being set st i in Seg n holds
(f2 . (a,x)) . i = a '&' (x . i)
; f1 = f2
now for a being Element of the carrier of Z_2
for x being Element of n -tuples_on BOOLEAN holds f1 . (a,x) = f2 . (a,x)let a be
Element of the
carrier of
Z_2;
for x being Element of n -tuples_on BOOLEAN holds f1 . (a,x) = f2 . (a,x)let x be
Element of
n -tuples_on BOOLEAN;
f1 . (a,x) = f2 . (a,x)A9:
len (f1 . (a,x)) = n
by CARD_1:def 7;
A10:
len (f2 . (a,x)) = n
by CARD_1:def 7;
now for i being Nat st 1 <= i & i <= len (f1 . (a,x)) holds
(f1 . (a,x)) . i = (f2 . (a,x)) . ilet i be
Nat;
( 1 <= i & i <= len (f1 . (a,x)) implies (f1 . (a,x)) . i = (f2 . (a,x)) . i )assume
( 1
<= i &
i <= len (f1 . (a,x)) )
;
(f1 . (a,x)) . i = (f2 . (a,x)) . ithen A11:
i in Seg n
by A9;
thus (f1 . (a,x)) . i =
a '&' (x . i)
by A7, A11, BSPACE:3
.=
(f2 . (a,x)) . i
by A8, A11, BSPACE:3
;
verum end; hence
f1 . (
a,
x)
= f2 . (
a,
x)
by FINSEQ_1:14, CARD_1:def 7, A10;
verum end;
hence
f1 = f2
by BINOP_1:2; verum