
theorem
  for C being non empty set, D being complex-membered non empty set for
f being Function of C,D, r being Complex for c being Element of C holds
  (f-r).c = f.c - r
proof
  let C be non empty set;
  let D be complex-membered non empty set;
  let f be Function of C,D, r be Complex;
  dom (f-r) = C by FUNCT_2:def 1;
  hence thesis by Def2;
end;
