
theorem ThGM3:
  for L being non trivial RATional positive-definite Z_Lattice,
      b being OrdBasis of L holds
  (GramMatrix(b))~ is Matrix of dim(L),F_Rat
  proof
    let L be non trivial RATional positive-definite Z_Lattice,
        b be OrdBasis of L;
    GramMatrix(b) is Matrix of dim(L),F_Rat by ZMODLAT2:45;
    hence thesis by INVMN2;
  end;
