Phi 270 F10 test 2

F10 test 2 topics

The following are the topics to be covered. The proportion of the test covering each will approximate the proportion of the classes so far that have been devoted to that topic. Your homework and the collection of old tests will provide specific examples of the kinds of questions I might ask.

Analysis. Be able to analyze the logical form of a sentence as fully as possible using conjunction, negation, and disjunction and present the form in both symbolic and English notation.

Synthesis. Be able to synthesize an English sentence that has a given logical form.

Derivations. Be able to construct derivations to show that entailments hold and to show that they fail. I may tell you in advance whether an entailment holds or leave it to you to check that using derivations. There may be a derivation where attachment rules (Adj and Wk) and detachment rules (MTP and MPT) may be used and where they will shorten the proof; but there will be other derivations where you must rely on the basic rules, either because detachment and attachment rules do not apply or because I tell you not to use them.


F10 test 2 questions

Analyze each sentence below in as much detail as possible, presenting the result in both symbols and English notation (i.e., both using symbolic notion, such as ‘∧’, and using the notation, such as ‘bothand’, that employs English words). Provide a key to your abbreviations of unanalyzed components, and be sure that they are complete and independent sentences. Try to respect any grouping in the English.

1.

Al presented his suggestion but didn’t get both the management and the union to agree to it.

answer
2.

Either Bob didn’t make the call or neither Carol nor Dave was home

answer

Synthesize an English sentence (the more idiomatic the better) that has the following analysis:

3.

(E ∧ ¬ F) ∨ (¬ E ∧ F)
(E: Dave contacted Ed; F: Dave contacted Fred)

answer

Use derivations to check whether each of the claims of entailment below holds. If one fails, present a counterexample by providing a table in which you calculate the truth values of the premises and conclusion on an extensional interpretation (i.e., an assignment of truth values) that divides an open gap. (Your table should indicate the value of any compound component by writing this value under the main connective of the component, and you should be sure to indicate the final value of each premise and the conclusion.)

Do not use attachment or detachment rules in 4-6. That is, do not use Adj or the rules MTP, MPT, and Wk of §4.3; instead use only the basic rules for exploiting resources, planning for goals, and closing gaps.

4. F ∧ ¬ G ⊨ ¬ (G ∧ H)
answer
5. ¬ (J ∧ K), K ∧ L ⊨ ¬ J
answer
6. ¬ (B ∧ C) ∨ A ⊨ ¬ C ∨ A
answer

You may use attachment and detachment rules in 7. While those rules can be used to shorten the derivation somewhat, it can also be completed without using them.

7. R ∨ ¬ S ⊨ ¬ (S ∧ ¬ R)
answer

F10 test 2 answers

1.

Al presented his suggestion but didn’t get both the management and the union to agree to it

Al presented his suggestionAl didn’t get both the management and the union to agree to his suggestion

Al presented his suggestion ∧ ¬ Al got both the management and the union to agree to his suggestion

Al presented his suggestion ∧ ¬ (Al got the management to agree to his suggestion ∧ Al got the union to agree to his suggestion)

P ∧ ¬ (M ∧ U)
both P and not both M and U

M: Al got the management to agree to his suggestion; P: Al presented his suggestion; U: Al got the union to agree to his suggestion

2.

Either Bob didn’t make the call or neither Carol nor Dave was home

Bob didn’t make the callneither Carol nor Dave was home

¬ Bob made the call ∨ ¬ either Carol or Dave was home

¬ Bob made the call ∨ ¬ (Carol was home ∨ Dave was home)

¬ B ∨ ¬ (C ∨ D)
either not B or not either C or D

B: Bob made the call; C: Carol was home; D: Dave was home

[¬ C ∧ ¬ D is also correct as an analysis of the second disjunct; and ¬ (B ∧ (C ∨ D)) is technically a correct analysis of the whole sentence, though it is much farther from the English.]

3.

(E ∧ ¬ F) ∨ (¬ E ∧ F) (E: Dave contacted Ed; F: Dave contacted Fred)

(Dave contacted Ed ∧ ¬ Dave contacted Fred) ∨ (¬ Dave contacted EdDave contacted Fred)

(Dave contacted EdDave didn’t contact Fred) ∨ (Dave didn’t contact EdDave contacted Fred)

(Dave contacted Ed but not Fred) ∨ (Dave didn’t contact Ed but did contact Fred)

Either Dave contacted Ed but not Fred, or he didn’t contact Ed but did contact Fred

4.
│F ∧ ¬ G3
├─
││G ∧ H2
│├─
2 Ext││G(4)
2 Ext││H
3 Ext││F
3 Ext││¬ G(4)
││●
│├─
4 Nc││⊥1
├─
1 RAA│¬ (G ∧ H)
5.
│¬ (J ∧ K)3
│K ∧ L2
├─
││J(5)
│├─
2 Ext││K(6)
2 Ext││L
││
││││●
│││├─
5 QED││││J4
│││
││││●
│││├─
6 QED││││K4
││├─
4 Cnj│││J ∧ K3
│├─
3 CR││⊥1
├─
1 RAA│¬ J
6.
│¬ (B ∧ C) ∨ A2
├─
││C(7)
│├─
│││¬ (B ∧ C)4
││├─
││││¬ A
│││├─
│││││││¬ B
││││││├─
│││││││○¬ B, ¬ A, C ⊭ ⊥
││││││├─
│││││││⊥6
│││││├─
6 IP││││││B5
│││││
││││││●
│││││├─
7 QED││││││C5
││││├─
5 Cnj│││││B ∧ C4
│││├─
4 CR││││⊥3
││├─
3 IP│││A2
││
│││A(8)
││├─
│││●
││├─
8 QED│││A2
│├─
2 PC││A1
├─
1 PE│¬ C ∨ A
ABC ¬(BC)A / ¬CA
FFT TF F
7. There are many possible answers; the following are three examples:
 
│R ∨ ¬ S3
├─
││S ∧ ¬ R2
│├─
2 Ext││S(5)
2 Ext││¬ R(4)
││
│││R(4)
││├─
│││●
││├─
4 Nc│││⊥3
││
│││¬ S(5)
││├─
│││●
││├─
5 Nc│││⊥3
│├─
3 PC││⊥1
├─
1 RAA│¬ (S ∧ ¬ R)
│R ∨ ¬ S3
├─
││S ∧ ¬ R2
│├─
2 Ext││S(4)
2 Ext││¬ R(3)
3 MTP││¬ S(4)
││●
│├─
4 Nc││⊥1
├─
1 RAA│¬ (S ∧ ¬ R)
 
│R ∨ ¬ S1
├─
││R(2)
│├─
2 Wk││¬ (S ∧ ¬ R)X, (3)
││●
│├─
3 QED││¬ (S ∧ ¬ R)1
││¬ S(4)
│├─
4 Wk││¬ (S ∧ ¬ R)X, (5)
││●
│├─
5 QED││¬ (S ∧ ¬ R)1
├─
1 PC│¬ (S ∧ ¬ R)