Homework for Philosophy 270, Fall 2009

Homework on §7.6—assigned Fri 11/13 and due Mon 11/16

(i) Use derivations to show:

∀x (Gx → ∀y Rxy), ∀x Gx ⊨ ∀x ∀y (Gy ∧ Rxy)

(ii) Analyze (and restate using unrestricted quantifiers):

If anyone who saw everything testified, the case was settled

(Bear in mind the difference between this sentence and each of the three other sentences you could get by replacing anyone by everyone or everything by anything.)