13. Symbolize the following arguments, and use either the long or short truth table method to test
their forms for validity. Do all the arguments that sound valid to you tum out to be valid?
a. This steak is tender only if it's fatty, and if it's fatty, it's not good for me. I won't eat it unless
it's good for me. Therefore, I won't eat this steak.
$(T \supset F) \cdot (F \supset \sim G), \sim G \supset \sim E / \therefore \sim E$
Invalid: let E = T, G = T, F = F, and T = F.