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 FINSEQ_1:def 18;
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_1:3;
(mlt (n |-> 0 ),R) . k =
((n |-> 0 ) . k) * (R . k)
by RVSUM_1:87
.=
0 * (R . k)
by A1, A3, FUNCOP_1:13
;
hence
(mlt (n |-> 0 ),R) . k = (n |-> 0 ) . k
by A1, A3, FUNCOP_1:13;
verum
end;
len (n |-> 0 ) = n
by FINSEQ_1:def 18;
hence
mlt (n |-> 0 ),R = n |-> 0
by A1, A2, FINSEQ_1:18; verum