reserve f for Function;
reserve n,k,n1 for Nat;
reserve r,p for Real;
reserve x,y,z for object;
reserve seq,seq1,seq2,seq3,seq9,seq19 for Real_Sequence;

theorem
  seq3 (#) (seq1 + seq2) = seq3 (#) seq1 + seq3 (#) seq2 by Th15;
