1. Aim: How can we review logic proofs for the upcoming regents exam? Homework- Logic proof questions (2) Do Now- Name three reasons used when solving a logic proof

2. Laws of Logic 1.Law of Contrapositive- P Q -Q  -P 2.Law of Contrapositive Inference- P  Q -Q -P 3.Law of Detachment- P  Q P Q  

3. Laws of Logic (Continued) 4.Law of Disjunctive Inference- P ∨ Q P ∨ Q -P -Q Q P 5.Demorgan’s Law - (P ∧ Q)=(-P) ∨ (-Q) -(P ∨ Q)=(-P) ∧ (-Q) 6. Chain Rule- P  Q Q  R P  R

4. Practice Proof 1. A  B StatementReason -B -A

5. Practice Questions (You can work in groups) 1.D  E3. P  S E  F P D -S ∨ P F P 2.Y ∨ Z4. H  I -ZI  J W  -YJ  k -WH  K

6. Practice Questions (Continued) 5. M ∨ N7. –A  -B -M-A L  -NC  B -L -C 6. U  V8. S  T U ∨ T T  U -V U  V T V  W W  X X  Y -Y -S

7. Homework 1.A  BStatementReason -A  -C -B -C 2.R  SStatementReason S  T -T R ∨ U U