
theorem ThSL4:
  for L being Z_Lattice, L1 being Z_Sublattice of L, w being Vector of L1 holds
  w is Vector of L
  proof
    let L be Z_Lattice, L1 be Z_Sublattice of L, w be Vector of L1;
    L1 is Submodule of L by ThSL1;
    hence thesis by ZMODUL01:25;
  end;
