University:
University of Pittsburgh
Course:
LSAT | Prep Course
Academic year:

2023
Views:

38

Pages:

2
Author:

mns81

LSAT PREP Sage Training – Week 4 All About Logic – Sufficient and Necessary Conditions  Elements of lawgic o Only two ways to interpret things. o J–F  The line or arrow means to the right or to the left of it.  Right means necessary condition.  Left means sufficient condition. The Contrapositive:       Logically equivalent statements They are genetic twins aka the same. Example: o All business school students are greedy. If you’re not greedy, you’re not a business school student. o All dogs are unselfish.  D - /S  / = Not  If something is selfish than it is not a dog.  S - /D Contrapositive is referring to the only other way in the lawgic language of expressing that conditional relationship. o English = many ways to express ideas o Lawgic = 2 ideas To get from 1 statement in lawgic to it’s contrapositive you apply a two-step process. o Switch the two symbols around the arrow. o Slap a negation sign on each symbol already negated, the negation goes away.  Not selfish becomes selfish. Try to not make the mistake of not doing both steps. o Doing just one and not the other will result in a mistake. Negation:    The / is the contradiction. “it’s” not the case that _____ Example: o The idea of rich. The opposite is not rich. o The rate of violent crimes has not risen in the last 5 years.  Can not assume the rate of violent crimes has fallen? Why?  Because the rate could have just stayed the same, or it could just not rise. Misc. Logical Indicators:  Is essential, is required, is/are.  Predicates, point to their subject and say that those subjects are essential, required, and necessary. “Neither” “Nor”  Neither the pandas nor the Koalas are cute enough to enter the zoo for free o Pandas are not cute enough to enter. o Koalas are not cute enough to enter.