Question 18 (8 points) Give a semi-formal, but careful, proof of the following argument. By "semi-formal", remember, that means that you can use all the official Fitch rules; and the rules from our official list of shortcuts; but just as in a formal proof, you still need to articulate your steps clearly, and use line numbers where appropriate. If you use any subproofs, be sure to clearly indicate where they start and stop. --> to prove: EzCube(z) Ex(Small(x) v ~Small(x)) No premises! [Note: This one is a bit on the harder side. If you can't quite finish it, then please be sure to show me the parts you can do, and then maybe explain in English how you would have liked to have proceeded but couldn't get the FOL to work. That way I can try to give you some partial credit.] Finally, translate that conclusion into colloquial English. (You may find it somewhat helpful to do this before attempting the informal proof, in fact.)