Homework on §7.7—assigned Mon 11/15 and due Wed 11/17

(i)

use a derivation to check the following and present a counterexample by using a diagram to describe a structure that divides an open gap:

∀x (Rax → Fx), Rab ⊨ ∀x (Rxa → Fx)

(ii)

analyze and restate using unrestricted quantifiers:

Nothing that anyone knew of explained the event

(iii)

synthesize an English sentence that has the following analysis:

(∀x: ¬ Ux) (∀y: Py) ¬ Nyx

(P: [ _ is a person]; N: [ _ noticed _ ]; U: [ _ was usual])