Give a derivation of each of the following formal theorems (a) ,( ),( ( )) (b) ( (

Give a derivation of each of the following formal theorems

(a) ϕ,(ϕ ⇒ ψ),(ϕ ⇒ (ψ ⇒ θ)) ⊢ θ

(b) ⊢ (ϕ ⇒ (ψ ≡ θ)) ≡ ((ϕ ⇒ ψ) ≡ (ϕ ⇒ θ)) (as usual, ≡ stands for ↔)