reserve X for ComplexUnitarySpace;
reserve g for Point of X;
reserve seq, seq1, seq2 for sequence of X;
reserve Rseq for Real_Sequence;
reserve Cseq,Cseq1,Cseq2 for Complex_Sequence;
reserve z,z1,z2 for Complex;
reserve r for Real;
reserve k,n,m for Nat;

theorem Th16:
  Sum(seq,1) = Sum(seq,0) + seq.1
proof
  Partial_Sums(seq).1 = Partial_Sums(seq).0 + seq.(0 + 1) by BHSP_4:def 1
    .= Partial_Sums(seq).0 + seq.1;
  hence thesis;
end;
