Problem Set 4, PL Trees

Due: July 1, 2025

1. Use PL trees to answer the following questions.

(a) Is the following argument valid? If not, read a counterexample off the tree. (2)

((A Λ ¬B) → C), A : ¬ (A → (B Λ C))

⃝ Valid.

⃝ Not Valid.

(b) Are the following propositions equivalent? If not, read a counterexample off the tree. (3)

((A Λ ¬B) → C), (¬ (A → B) → C)

⃝ Equivalent.

⃝ Not equivalent.