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

Laws of Logic

1. Law of Contrapositive- P Q -Q -P

2. Law of Contrapositive Inference- PQ -Q

-P3. Law of Detachment- PQ

P Q

Laws of Logic (Continued)

4. Law of Disjunctive Inference- P∨Q P∨Q -P -Q

Q P5. Demorgan’s Law -(P∧Q)=(-P) ∨(-Q)

-(P∨Q)=(-P) ∧ (-Q)6. Chain Rule- PQ QR PR

Practice Proof

1. AB Statement Reason-B-A

Practice Questions (You can work in groups)

1. DE 3. PS EF P

D -S∨PF P

2. Y∨Z 4. HI -Z IJ

W-Y Jk -W HK

Practice Questions (Continued)5. M∨N 7. –A-B -M -A L-N CB

-L -C6. UV 8. ST

U∨T TU -V UV

T VW WX

XY-Y -S

Homework1. AB Statement Reason -A-C

-B-C

2. RS Statement ReasonST

-TR∨U

U