let n be Element of NAT ; for R being Element of n -tuples_on REAL holds mlt ((n |-> 0),R) = n |-> 0
let R be Element of n -tuples_on REAL; mlt ((n |-> 0),R) = n |-> 0
A1:
len (mlt ((n |-> 0),R)) = n
by CARD_1:def 7;
A2:
for k being Nat st 1 <= k & k <= len (mlt ((n |-> 0),R)) holds
(mlt ((n |-> 0),R)) . k = (n |-> 0) . k
proof
let k be
Nat;
( 1 <= k & k <= len (mlt ((n |-> 0),R)) implies (mlt ((n |-> 0),R)) . k = (n |-> 0) . k )
assume
( 1
<= k &
k <= len (mlt ((n |-> 0),R)) )
;
(mlt ((n |-> 0),R)) . k = (n |-> 0) . k
then A3:
k in Seg (len (mlt ((n |-> 0),R)))
by FINSEQ_1:1;
(mlt ((n |-> 0),R)) . k =
((n |-> 0) . k) * (R . k)
by RVSUM_1:60
.=
0 * (R . k)
by A1, A3, FUNCOP_1:7
;
hence
(mlt ((n |-> 0),R)) . k = (n |-> 0) . k
by A1, A3, FUNCOP_1:7;
verum
end;
len (n |-> 0) = n
by CARD_1:def 7;
hence
mlt ((n |-> 0),R) = n |-> 0
by A1, A2, FINSEQ_1:14; verum