Determine whether the following statements are true or false. You do not need to justify your answer.

(a) ; ⊂ ;
(b) a ∈ {a}
(c) ; ⊆ {a}
(d) ; ∈ {a}
(e) {;} ∈ {;}
(f) {{;}} ⊆ {{;}, {;}}