let RNS1, RNS2 be RealLinearSpace; ( RLSStruct(# the carrier of RNS1, the ZeroF of RNS1, the addF of RNS1, the Mult of RNS1 #) = RLSStruct(# the carrier of RNS2, the ZeroF of RNS2, the addF of RNS2, the Mult of RNS2 #) implies for Ft being FinSequence of RNS1
for FFr being FinSequence of RNS2 st Ft = FFr holds
Sum Ft = Sum FFr )
assume A1:
RLSStruct(# the carrier of RNS1, the ZeroF of RNS1, the addF of RNS1, the Mult of RNS1 #) = RLSStruct(# the carrier of RNS2, the ZeroF of RNS2, the addF of RNS2, the Mult of RNS2 #)
; for Ft being FinSequence of RNS1
for FFr being FinSequence of RNS2 st Ft = FFr holds
Sum Ft = Sum FFr
let F be FinSequence of RNS1; for FFr being FinSequence of RNS2 st F = FFr holds
Sum F = Sum FFr
let Fv be FinSequence of RNS2; ( F = Fv implies Sum F = Sum Fv )
assume A2:
F = Fv
; Sum F = Sum Fv
set T = RNS1;
set V = RNS2;
consider f being sequence of the carrier of RNS1 such that
A3:
Sum F = f . (len F)
and
A4:
f . 0 = 0. RNS1
and
A5:
for j being Nat
for v being Element of RNS1 st j < len F & v = F . (j + 1) holds
f . (j + 1) = (f . j) + v
by RLVECT_1:def 12;
consider fv being sequence of the carrier of RNS2 such that
A6:
Sum Fv = fv . (len Fv)
and
A7:
fv . 0 = 0. RNS2
and
A8:
for j being Nat
for v being Element of RNS2 st j < len Fv & v = Fv . (j + 1) holds
fv . (j + 1) = (fv . j) + v
by RLVECT_1:def 12;
defpred S1[ Nat] means ( $1 <= len F implies f . $1 = fv . $1 );
A9:
for i being Nat st S1[i] holds
S1[i + 1]
proof
let i be
Nat;
( S1[i] implies S1[i + 1] )
assume A10:
S1[
i]
;
S1[i + 1]
assume A11:
i + 1
<= len F
;
f . (i + 1) = fv . (i + 1)
then A12:
i + 1
in dom F
by NAT_1:11, FINSEQ_3:25;
then
F . (i + 1) = F /. (i + 1)
by PARTFUN1:def 6;
then A13:
f . (i + 1) = (f . i) + (F /. (i + 1))
by A5, A11, NAT_1:13;
A14:
Fv /. (i + 1) = Fv . (i + 1)
by A2, A12, PARTFUN1:def 6;
thus f . (i + 1) =
(fv . i) + (Fv /. (i + 1))
by A10, A11, A13, NAT_1:13, A1, A2
.=
fv . (i + 1)
by A2, A8, A11, NAT_1:13, A14
;
verum
end;
A15:
S1[ 0 ]
by A4, A7, A1;
for n being Nat holds S1[n]
from NAT_1:sch 2(A15, A9);
hence
Sum F = Sum Fv
by A2, A3, A6; verum