
theorem LM2:
for A be non empty closed_interval Subset of REAL,
    rho be Function of A,REAL,
    t be Division of A,
    F be var_volume of rho,t
 holds 0 <= Sum(F)
proof
  let A be non empty closed_interval Subset of REAL,
      rho be Function of A,REAL,
      t be Division of A,
      F be var_volume of rho,t;
  for k be Nat st k in dom F holds 0 <= F.k by LM1;
  hence 0 <= Sum(F) by RVSUM_1:84;
end;
