Determining whether an argument is valid is easy to mechanically test for in some cases. For example, there is the argument: “If the apple I am holding is red then I am happy. The apple I am holding is red. Therefore, I am happy.” This is an easy one to test for since there are only two possibilities for whether or not the sentence “the apple I am holding is red” is true and two possibilities for whether or not the sentence “I am happy” is true. Thus, there are only 4 ways the “world” could be. Either my apple is red and I am happy, my apple is not red and I am happy, my apple is red and I am not happy, or my apple is not red and I am not happy. Now, on to the argument. In the argument, we are assuming the conditional “if the apple I am holding is red then I am happy’ and that “the apple I am holding is red”. Our second assumption limits us to two possibilities: either the apple I am holding is red and I am happy, or the apple I am holding is red and I am not happy. F