Homework for Philosophy 270, Fall 2012
Homework on §7.6—assigned Fri 11/9 and due Mon 11/12
(to PDF format)
Use derivations to show:
∀x (Fx → ∀y Rxy) ⊨ ∀x ∀y (Fy → Ryx)
Analyze (and restate using unrestricted quantifiers):
If anyone heard the warning, the storm didn’t surprise everyone
(Bear in mind the difference between this sentence and each of the three other sentences you could get by replacing anyone by everyone or vice versa.)