Math 39 Homework #12 Sixty minutes of thinking of any kind is bound to lead to confusion and unhappiness. James Thurber

	Reading Read what we will cover in the next class: 4.1. When reading 4.1 pay special attention to the following concepts: the axioms and rules of deduction of K(L), deduction, consequences, Propositions 4.3, 4.4, The Soundness Theorem (Proposition 4.5), The Deduction Theorem (Prop 4.8), and the many miscellaneous propositions that complete the remainder of this section most of which are just carrying results we know for L over to K(L).

	Problems The following problems are due by the beginning of class on Friday 10/23. 3.4: 21, 22b,c,d, 23. Give two specific examples of each of the axiom schemes in K(L), one which is a closed wf, and the other of which is not closed.