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
  abs(seq9/"seq)=abs(seq9)/"abs(seq)
proof
  thus abs(seq9/"seq)=abs(seq9)(#)abs(seq") by Th50
    .=abs(seq9)/"abs(seq) by Th52;
end;
