## Tags » Irving Copi

#### Symbolic Logic 5E: 3.5

“For each of the following arguments, construct both a formal proof of validity and an indirect proof and compare their length”

1.

Formal Proof

1. A ∨(B ∧ C)
2. 152 more words
Analytic

#### Symbolic Logic 5E: 3.4

“Give conditional proofs of validity for Exercises 21*, 22, 23, 24, and 25 on pages 47-48.”

21. In back of book.

22.

1. (T→E) ∧ (A→L) …Therefore, (T ∧ A)→(E ∧ L)
2. 105 more words
Analytic

#### Symbolic Logic 5E: 3.3

“Prove the validity of each of the following arguments by the method of assigning truth values”

1. In back of book.

2. E=T ; F=T ; G=F ; H=F ; I=F… 78 more words

Analytic

#### Symbolic Logic 5E: 3.2, III, Second Half

Note: I cheated and used conditional proof (CP) for problems 27-29. I don’t think this is such an egregious offense, as CP is introduced a mere four pages later. 567 more words

Analytic

#### Symbolic Logic 5E: 3.2, III, First Half

“Construct a formal proof of validity for each of the following arguments”

1. In back of book.

2.

1. C …Therefore, D→C
3. 298 more words
Analytic

#### Symbolic Logic 5E: 3.2, II

“Each of the following is a formal proof of validity for the indicated argument. State the ‘justification’ for each line that is not a premiss” 393 more words

Analytic

#### Symbolic Logic 5E: 3.2, I

“For each of the following arguments, state the Rule of Inference by which its conclusion follows from its premiss”

1. Commutation.
2. Material Implication.
3. Transposition.
4. De Morgan’s Theorem.
5. 23 more words
Analytic