Give the reason(s) for each step needed to show that the following argument is valid.
[p ∧ (p → q) ∧ (s ∨ r) ∧ (r → ¬q)] → (s ∨ t)
Steps Reasons
(1) p
(2) p → q
(3) q
(4) r → ¬q
(5) q → ¬r
(6) ¬r
(7) s ∨ r
(8) s
(9) ∴ s ∨ t