 reserve n for Nat;
 reserve s1 for sequence of Euclid n,
         s2 for sequence of REAL-NS n;

theorem
  for r being Real, p,q being FinSequence of REAL
  holds len (p ^ <*r*> ^ q) = len p + len q + 1
  proof
    let r be Real, p,q be FinSequence of REAL;
A1: len (p ^ <*r*> ^ q) = len( p ^ <*r*>) + len q by FINSEQ_1:22
                       .= len p + len <*r*> + len q by FINSEQ_1:22;
    len <*r*> = 1 by FINSEQ_1:40;
    hence thesis by A1;
  end;
