reserve V,W for Z_Module;
reserve T for linear-transformation of V,W;
reserve T for linear-transformation of V,W;
reserve l for Linear_Combination of V;
reserve V,W for Z_Module;
reserve l for Linear_Combination of V;
reserve T for linear-transformation of V,W;

theorem
  for X being Subset of V st X is linearly-dependent holds
  ex l being Linear_Combination of X st Carrier l <> {} & Sum l = 0.V;
