(20) Accepting the following premises, conclude -¬p: 1. q - (r As) 2. ¬(r V t) 3. ¬s → 4 4. ¬(p A s)

EXERCISES 1. Compute the truth values of the following, given that A, B, and C are true and X, Y, and Z are false. b. ~A~C d. (Xv A) ~B f. ~(Av B) (X v Y) h. (A=X) = (B = Y) j. (~X~Y) = (A >~(X • Y)) 1. ~((A v B) v C) v (CƆ ~ (X v ~A)) n. ~[((A~B) ~C) ~X] p. ~~(A ~(B ~(C ~(X VY)))) r. ((XY) v (A•~B)) ((X v A) · (Y v~B))

16. Consider the following propositions: r = “ODD(N) = T," m = "the output goes to the monitor," and p = "the output goes to the printer." Translate the following, as in Exercise 15. (a) The output goes to the monitor if ODD(N) = T. (b) The output goes to the printer whenever ODD(N) = T is not true. (c) ODD(N) = T only if the output goes to the monitor. (d) The output goes to the monitor if the output goes to the printer. (e) ODD(N) = T or the output goes to the monitor if the output goes to the printer.

7. Describe the following combined propositions as English sentences if s = heavy snow, C = flight canceled, and d=there are delays a. s→C b. sAc (s V c) • (d V c) e. sA (d V c) С. d d. s- 8. Convert the following expressions into DNF format (where ! is NOT) a. (x+y!z)(!x+y+!z) b. (ху)!(х+y) 9. Are the following expressions satisfiable? a. (x+y)(!x+!z)(!y+z)(x+!z+!y) b. (x+y)(!x+!z)(!y+z)(x+!z+!y)(!x+y+!z) 10. Draw circuit for the following expression !xy(!x+y)(x+y+!z)