reserve rseq, rseq1, rseq2 for Real_Sequence;
reserve seq, seq1, seq2 for Complex_Sequence;
reserve k, n, n1, n2, m for Nat;
reserve p, r for Real;
reserve z for Complex;
reserve Nseq,Nseq1 for increasing sequence of NAT;

theorem Th27:
  Partial_Sums(seq1)+Partial_Sums(seq2) = Partial_Sums(seq1+seq2)
  by SERIES_1:5;
