Construct derivations to demonstrate the following claims. You may use any rules of PD of PD+
1. ⊢ (Fa ∨ ∼Fb) ∨ ∼(∀x)Fx
2. {(∀z)Mz & (∀z)(Lz ∨ ~Nz)} ⊢ (∀x)[(Mx & Nx) ⊃ Lx]
3. ⊢ (∀x)Px ∨ (∃x)~Px
4. {(∀x)(Fxa ⊃ Fax), (∃x)(Hx & ~Fax)} ⊢ ~(∀y)(Hy ⊃ Fya)