reserve a,b,i,j,k,l,m,n for Nat;

theorem DAB:
  for a,b be Real, n be Nat holds
    (a,b) Subnomial n = ((a,1) Subnomial n) (#) ((1,b) Subnomial n)
  proof
    let a,b be Real, n be Nat;
    (a*1,b*1) Subnomial n = ((a,1) Subnomial n) (#) ((1,b) Subnomial n) by ST;
    hence thesis;
  end;
