Determine whether the following symbolized arguments are valid or invalid by identifying the form of each. In some cases the argument must be rewritten using double negation or commutativity before it has a named form. Those arguments without a specific name are invalid. G ⊃ ∼R G ∼R a. DS—invalid. b. DA—valid. c. MT—valid. d. HS—valid. e. MP—valid.