reserve m,n for Nat;
reserve r for Real;
reserve c for Element of F_Complex;

theorem Th21:
  for f being RAT-valued Polynomial of F_Complex holds
  f is Polynomial of F_Rat
  proof
    let f be RAT-valued Polynomial of FC;
    rng f c= RAT by RELAT_1:def 19;
    then reconsider f1 = f as sequence of Fq by FUNCT_2:6;
    f1 is finite-Support by Lm1,ALGSEQ_1:def 1;
    hence thesis;
  end;
