Question 1
Consider this proof, (1.)E /∴ C v (E v D) (2.) E v D (3.) (E v D) v C (4.) C v (E v D) What is the justification for line 2?
◦ 1 Simp
◦ 1 Add
◦ 1 Com
Question 2
Consider this proof, (1.)E /∴ C v (E v D) (2.) E v D (3.) (E v D) v C (4.) C v (E v D) What is the justification for line 3?
◦ 1, 2 DS
◦ 2, 1 Cond
◦ 2 Add