1)     “p → q”  (“If p then q” -- 'material implication')

2)     “p v q”    (“p or q” -- 'disjunction')

3)     “p v ~ p” (“p or not p” – i.e., ‘law of excluded middle’)

4)     “~ (p & ~ p)” (“not both p and not p” – i.e., ‘law of non-contradiction’).