นิตยสาร สสวท. ฉบับที่ 245

ปีที่ 52 ฉบับที่ 245 พฤศจิกายน - ธันวาคม 2566 45 T 1 p → p ˅ q Law of Addition q → p ˅ q T 2 p ˄ q → p Law of Simplification p ˄ q → q T 3 p ˄ (p → q) → q Modus Ponens T 4 ~q ˄ (p → q) → ~p Modus Tollens T 5 p → q ↔ ~q → ~p Law of Contrapositive T 6 (p → q) ˄ (q → r) → (p → r) Law of Syllogism T 7 p ↔ p Reflexive Law T 8 p ˅ p ↔ p Idempotent Law p ˄ p ↔ p T 9 p ˅ ~p Law of Excluded Middle T 10 ~(~p) ↔ p Double Negation T 11 p ˅ q ↔ q ˅ p Commutative Laws p ˄ q ↔ q ˄ p T 12 p ˅ (q ˅ r) ↔ (p ˅ q) ˅ r Associative Laws p ˄ (q ˄ r) ↔ (p ˄ q) ˄ r T 13 p ˅ (q ˄ r) ↔ (p ˅ q) ˄ (p ˅ r) Distributive Law p ˄ (q ˅ r) ↔ (p ˄ q) ˅ (p ˄ r) T 14 ~(p ˅ q) ↔ ~p ˄ ~q de Morgan‘s Laws ~(p ˄ q) ↔ ~p ˅ ~q T 15 {~p → (q ˄ ~q)} → p Law of Absurdity T 16 (p → r) ˄ (q → r) ↔ (p ˅ q) → r Proof by Cases T 17 (p → q) ↔ ~p ˅ q Equivalence Form for Implication T 18 ~(p → q) ↔ p ˄ ~q Law of Negation for Implication T 19 ~p ˄ (p ˅ q) → q Disjunctive Syllogism T 20 (p → q) → (p → p ˄ q) T 21 (p → q) → (p ˅ r → q ˅ r) T 22 (p → q) → (p ˄ r → q ˄ r) T 23 (p → q) ˄ (p → r) ↔ (p → q ˄ r) T 24 (p ˄ q → r) ↔ {p → (q → r)} T 25 (p → q ˄ ~q) → ~p T 26 (p ↔ q) ↔ (p → q) ˄ (p → q) T 27 [(p ↔ q) ˄ (r → s) ˄ (p ˅ r)] → q ˅ s Constructive Dilemma T 28 [(p → q) ˄ (r → s) ˄ (~q ˅ ~s)] → ~p ˅ ~r Destructive Dilemma