Problem 2 Download Lecture Slides 28, Part I. Do the two exercises on page 14. Note that, in each of the two exercises, you have to show that I, i.e., that I semantically implies y. This is a semantic assertion, it is not a formal proof-theoretic assertion, which is written as I p. So, as a first step in each of the two exercises, you have to explain how you can go from "Ty" to a set of (closed) first-order wff's to which you can apply the ground tableau method, and then obtain a closed tableau from which you can draw the desired conclusion. 0

Fig: 1