let k be Nat; for h being complex-valued FinSequence holds (h,0) +...+ (h,k) = (h,1) +...+ (h,k)
let h be complex-valued FinSequence; (h,0) +...+ (h,k) = (h,1) +...+ (h,k)
not 0 in dom h
by FINSEQ_3:25;
then A1:
h . 0 = 0
by FUNCT_1:def 2;
(h,0) +...+ (h,k) = (h . 0) + ((h,(0 + 1)) +...+ (h,k))
by Th13;
hence
(h,0) +...+ (h,k) = (h,1) +...+ (h,k)
by A1; verum