Question 1
By applying the rules
MT and
DN to“~ F ⊃ (~ L v M), ~ (~ L v M)” we can deduce
◦ ~ L v M)
◦ F
◦ ~ F
Question 2
By applying the rules
DS and
DN to “~ (B v C) v (C ≡ D), B v C” we can deduce (6.) (I ∙ ~ D) ∙ ~L What is the justification for line 3?
◦ 1, 3 MP
◦ 1, 3 Bicond
◦ 2 Simp