Determine Whether the Given Argument Is Valid or Invalid $\lor$

question 111

Essay

determine whether the given argument is valid or invalid. If it is valid, provide a derivation of the conclusion from the premises. If it is invalid, provide a counterexample.
-1. (∀x)[Fx ⊃ (Gx $\lor$ Hx)]
2. (∀x)(Gx ⊃ ∼Ix)
3. ∼(∃x)(Hx • Ix)
4. Fg / ∼Ig