The decision problem is studied for fragments of second-order linear logic without modalities. It is shown that the structural rules of contraction and weakening may be simulated by second-order propositional quanti ers and the multiplicative connectives. Among the consequences are the undecidability of the intuitionistic second-order fragment of propositional multiplicative linear logic and the undecidability of multiplicative linear logic with rst-order and second-order quanti ers.