Phi 270 F96 test 4
(questions 1-3 are from quiz 4 and 4-9 are from quiz 5 out of 6 quizzes—these two quizzes addressed the part of the course your test is designed to cover)
1. Identify individual terms and quantifier phrases in the following sentence and indicate links between pronouns and their antecedents. (You can do this by marking up an English sentence; you are not being asked to provide a symbolic analysis.)
  Al called everyone who left him a message concerning the accident and told them he had seen it.
answer
Analyze the following generalizations in as much detail as possible. Provide a key to the non-logical vocabulary (upper and lower case letters) appearing in your answer and restate the result using an unrestricted quantifier.
2. Every employee received the letter.
answer
3. Among bystanders, Sam interviewed only soldiers.
answer
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.
4. If anyone guessed the number, the prize was awarded.
answer
5. Everyone who worked on any part of the project was honored.
answer
Synthesize an English sentence whose analysis would yield the following form.
6. (∀x: Px) ¬ ∀y Axy
A: [ _ ate _ ]; P: [ _ is a person]
answer
Use derivations to establish the validity of the following arguments. You may use attachment rules.
7.
∀x Fx
∀x Gx
∀x (Fx ∧ Gx)
answer
8.
∀x (Fx → Rxa)
∀x (Rxa → ∀y Ryx)
∀x ∀y (Fy → Rxy)
answer
9. Use a derivation to show that the following argument is not valid and describe a structure dividing one of the derivation’s open gaps. (You will not need the rules UG+ and ST introduced in §7.8 that are designed to avoid unending gaps.)
 
∀x Rxx
Rab → ∀x Rxa
answer

Phi 270 F96 test 4 answers
1.
 
                      
                      
                       
Alcalledeveryone who lefthim a messageconcerningthe accidentand toldthem hehad seenit
     
    
T Q  Q T      
[it could instead have a message concerning the accident as its antecedent]
2. Every employee received the letter
Every employee is such that (he or she received the letter)
(∀x: x is an employee) x received the letter
(∀x: Ex) Rxl
∀x (Ex → Rxl)
E: [ _ is an employee]; R: [ _ received _ ]; l: the letter
3. Among bystanders, Sam interviewed only soldiers
Among bystanders, only soldiers are such that (Sam interviewed them)
(∀x: x was a bystander ∧ ¬ x was a soldier) ¬ Sam interviewed x
(∀x: Bx ∧ ¬ Sx) ¬ Isx
∀x ((Bx ∧ ¬ Sx) → ¬ Isx)
B: [ _ was a bystander]; I: [ _ interviewed _ ]; S: [ _ was a soldier]; s: Sam
4. If anyone guessed the number, the prize was awarded
Everyone is such that (if he or she guessed the number, the prize was awarded)
(∀x: x is a person) (if x guessed the number, the prize was awarded)
(∀x: Px) (x guessed the number → the prize was awarded)
(∀x: Px) (Gxn → Ap)
P: [ _ is a person]; G: [ _ guessed _ ]; n: the number
5. Everyone who worked on any part of the project was honored
Every part of the project is such that (everyone who worked on it was honored)
(∀x: x is a part of the project) everyone who worked on x was honored
(∀x: Rxj) (∀y: y is a person who worked on x) y was honored
(∀x: Rxj) (∀y: y is a person ∧ y worked on x) Hy
(∀x: Rxj) (∀y: Py ∧ Wyx) Hy
H: [ _ was honored]; P: [ _ is a person]; R: [ _ is a part of _ ]; W: [ _ worked on _ ]; j: the project
6. (∀x: x is a person) ¬ ∀y x ate y
(∀x: x is a person) ¬ x ate everything
No one is such that (he or she ate everything)
No one ate everything
7.
│∀x Fx a:2
│∀x Gx a:3
├─
│ⓐ 
2 UI ││Fa (5)
3 UI ││Ga (6)
││
│││●
││├─
5 QED │││Fa 4
││
│││●
││├─
6 QED │││Ga 4
│├─
4 Cnj ││Fa ∧ Ga 1
├─
1 UG │∀x (Fx ∧ Gx) 1
8.
│∀x (Fx → Rxa) c:4
│∀x (Rxa → ∀y Ryx) c:6
├─
│ⓑ
││ⓒ
││││Fc (5)
│││├─
4 UI ││││Fc → Rca 5
5 MPP ││││Rca (7)
6 UI ││││Rca → ∀y Ryc 7
7 MPP ││││∀y Ryc b:8
8 UI ││││Rbc (9)
││││●
│││├─
9 QED ││││Rbc 3
││├─
3 CP │││Fc → Rbc 2
│├─
2 UG ││∀y (Fy → Rby) 1
├─
1 UG │∀x ∀y (Fy → Rxy)
9.
│∀x Rxx a:1,b:2,c:5
├─
1 UI │Raa
2 UI │Rbb
││Rab
│├─
││ⓒ
5 UI │││Rcc
│││
││││ ¬ Rca
│││├─
││││ ○ Raa,Rab,Rbb,Rcc,¬Rca ⇏ ⊥
│││├─
││││⊥ 6
││├─
6 IP │││Rca 4
│├─
4 UG ││∀x Rxa 3
├─
3 CP │Rab → ∀x Rxa