Phi 270 F99 test 4 in pdf format
Analyze the following sentences in as much detail as possible, providing a key to the non-logical vocabulary (upper and lower case letters) appearing in your answer.
1. Sam invited every vertebrate to the party, but only people accepted his invitation
[answer]
2. Tom didn't send anything to the printer
[answer]
3. No game that every child liked was complete
[answer]
Synthesize an English sentence whose analysis would yield the following form.
4. (∀x: Px) (∀y: Ry ∧ Txy) Sy
[P: λx (x is a person); R: λx (x is a room); S: λx (x was reserved); T: λxy (x thought of y)]
[answer]
Use derivations to establish the validity of the following arguments. You may use attachment rules.
5.
∀x (Fx → Gx)
∀x Fx → ∀x Gx
[answer]
6.
∀x (∀y: Fyx) ¬ Py
(∀x: Px) ∀y ¬ Fxy
[answer]
7. Use a derivation to show that the following argument is not valid and describe a structure (by using either a diagram or tables) that divides one of the derivation's open gaps.
∀x (∀y: Fy) ¬ Rxy
∀x Rxx
∀x ∀y ¬ Rxy
[answer]

Phi 270 F99 test 3 answers
1.

Sam invited every vertebrate to the party, but only people accepted his invitation

Sam invited every vertebrate to the partyonly people accepted Sam's invitation

every vertebrate is such that (Sam invited it to the party)only people are such that (they accepted Sam's invitation)

(∀x: x is a vertebrate) Sam invited x to the party ∧ (∀x:¬ x is a person) ¬ x accepted Sam's invitation

(∀x: Vx) Isxp ∧ (∀x:¬ Px) ¬ Ax(Sam's invitation)

(∀x: Vx) Isxp ∧ (∀x: ¬ Px) ¬ Ax(is)
[A: λxy (x accepted y); I: λxyz (x invited y to z); P: λx (x is a person); V: λx (x is a vertebrate); i: λx (x 's invitation); p: the party; s: Sam]
2.

Tom didn't send anything to the printer

everything is such that (Tom didn't send it to the printer)

∀x Tom didn't send x to the printer

∀x ¬ Tom sent x to the printer

∀x ¬ Stxp
[S: λxyz (x sent y to z); p: the printer; t: Tom]
3.

No game that every child liked was complete

No game that every child liked is such that (it was complete)

(∀x: x was a game that every child liked) ¬ x was complete

(∀x: x was a gameevery child liked x) ¬ Cx

(∀x: x was a gameevery child is such that (he or she liked x)) ¬ Cx

(∀x: Gx ∧ (∀y: y was a child) y liked x) ¬ Cx

(∀x: Gx ∧ (∀y: Dy) Lyx) ¬ Cx
[C: λx (x was complete); D: λx (x was a child); G: λx (x was a game); L: λxy (x liked y)]
4.

(∀x: x is a person) (∀y: y is a room ∧ x thought of y) y was reserved

(∀x: x is a person) (∀y: y is a room x thought of) y was reserved

(∀x: x is a person) every room x thought of was such that (it was reserved)

(∀x: x is a person) every room x thought of was reserved

everyone is such that (every room he or she thought of was reserved)

every room anyone thought of was reserved

5.
│∀x (Fx → Gx) a:3
├─
││∀x Fx a:4
│├─
││ⓐ
3 UI │││Fa → Ga 5
4 UI │││Fa (5)
5 MPP │││Ga (6)
│││●
││├─
6 QED │││Ga 2
│├─
2 UG ││∀x Gx 1
├─
1 CP │∀x Fx → ∀x Gx
6.
│∀x (∀y: Fyx) ¬ Py b:4
├─
│ⓐ
││Pa (6)
│├─
││ⓑ
││││Fab (5)
│││├─
4 UI ││││(∀y: Fyb) ¬ Py a:5
5 SB ││││¬ Pa (6)
││││●
│││├─
6 Nc ││││⊥ 3
││├─
3 RAA │││¬ Fab 2
│├─
2 UG ││∀y ¬ Fay 1
├─
1 RUG │(∀x: Px) ∀y ¬ Fxy
7.
│∀x (∀y: Fy) ¬ Rxy a:4,b:5
│∀x Rxx a:6,b:7
├─
│ⓐ
││ⓑ
││││Rab (9)
│││├─
4 UI ││││(∀y: Fy) ¬ Ray a:8,b:9
5 UI ││││(∀y: Fy) ¬ Rby b:10,a:11
6 UI ││││Raa (8)
7 UI ││││Rbb (10)
8 SC ││││¬ Fa
9 SC ││││¬ Fb
10 SC ││││¬ Fb
││││
││││││¬ Fa
│││││├─
││││││○ ¬Fa,¬Fb,Rab,Raa,Rbb ⇏ ⊥
│││││├─
││││││⊥
││││├─
│││││Fa 11
││││
│││││¬ Rba
││││├─
│││││○ ¬Fa,¬Fb,Rab,Raa,Rbb,¬Rba ⇏ ⊥
││││├─
│││││⊥ 11
│││├─
11 MCR ││││⊥ 3
││├─
3 RAA │││¬ Rab 2
│├─
2 UI ││∀y ¬ Ray 1
├─
1 UI │∀x ∀y ¬ Rxy
  The structure below divides both gaps