
theorem
  for L being RATional Z_Lattice, b being OrdBasis of L holds
  Det GramMatrix(b) in F_Rat
  proof
    let L be RATional Z_Lattice, b be OrdBasis of L;
    GramMatrix(b) is Matrix of dim(L), F_Rat by ThGM1;
    hence thesis by LmGM11;
  end;
