Philosophy 1102 Instructor: Richard Johns Problem Set 10 Hand in your answers during class on Wednesday, November 27. [Please write your proofs neatly, using enough paper so that each proof is all in one place. Use only the rules provided in the handout “Rules of F+”.] 1. Show that the argument below is FO con by giving a formal proof.[6 marks]2. Show that the argument below is FO con by giving a formal proof. [6 marks]3. Show that the argument below is FO con by giving a formal proof. [6 marks] [N.B. you can eliminate the xand yquantifiers in one step if you like, since they’re touching.] 4. Show that the argument below is FO con by giving a formal proof. [6 marks]
5. Show that the argument below is notFO con, by doing the following: [5 marks] (a) Write the argument as it appears through FO goggles (b) Provide a counter-example set of predicates to replace the nonsense predicates used in part (a), and (c) Draw a counter-example world, for the new argument (with the new predicates) 6. By giving a formal proof, show that the argument in Qu. 5 becomes FO con when suitable shape axioms (see below) are added as premises. (Cite the axioms as ‘A1’, ‘A2’, etc.)[7 marks] Shape Axioms A1. x (Cube(x) Tet(x)) A2. x (Tet(x) Dodec(x)) A3. x (Dodec(x) Cube(x)) A4. x (Tet(x) Dodec(x) Cube(x)) A5. x y ((Cube(x) Cube(y)) →SameShape(x, y)) A6. x y ((Dodec(x) Dodec(y)) →SameShape(x, y)) A7. x y ((Tet(x) Tet(y)) →SameShape(x, y)) A8. x y ((SameShape(x, y) Cube(x)) →Cube(y)) A9. x y ((SameShape(x, y) Dodec(x)) →Dodec(y)) A10. x y ((SameShape(x, y) Tet(x)) →Tet(y))7. Show that the argument below is FO con by giving a formal proof.[7 marks] 8. Show that the argument below is FO con by giving a formal proof. [7 marks] [Make sure you understand what the first premise says. An important question then is: Does Celine love Celine?]