LSAT · LSAT

LSAT Logic Terminology

Core formal logic and logical reasoning vocabulary tested on the LSAT, framed as original concept cards.

42 cards · basic cards · AI-written, checked twice. Edit anything.

Study this set free Get FlashKeepers for iPhone
What is a conditional statement in logic?
A statement in the form 'if P, then Q' where P is the antecedent and Q is the consequent.
What is the contrapositive of 'If P, then Q'?
If not Q, then not P. The contrapositive is logically equivalent to the original conditional.
Is the contrapositive logically equivalent to the original conditional?
Yes. A statement and its contrapositive are always logically equivalent and have identical truth conditions.
What is the converse of 'If P, then Q'?
If Q, then P. The converse is NOT logically equivalent to the original.
What is the inverse of 'If P, then Q'?
If not P, then not Q. The inverse is NOT logically equivalent to the original.
What is a necessary condition?
A condition that must be true for something else to be true. If P is necessary for Q, then Q cannot occur without P.
What is a sufficient condition?
A condition that, if true, guarantees something else is true. If P is sufficient for Q, then P guarantees Q.
In 'If P, then Q', which is the necessary condition and which is sufficient?
P is sufficient for Q; Q is necessary for P.
What is the negation of a statement?
The opposite truth value. If a statement is true, its negation is false, and vice versa.
What is a disjunction in logic?
A statement joined by 'or,' true when at least one component is true. In formal logic, this is usually inclusive (or both).
What is a conjunction in logic?
A statement joined by 'and,' true only when both components are true.
What are De Morgan's Laws?
Not (P and Q) is equivalent to (not P) or (not Q). Not (P or Q) is equivalent to (not P) and (not Q).
What is logical equivalence?
Two statements are logically equivalent if they have the same truth value in all possible scenarios.
What is an assumption in logical reasoning?
An unstated premise that must be true for an argument to work. The argument depends on it even though it is not explicitly stated.
What is a premise in an argument?
A stated reason or evidence offered to support the conclusion. Premises are the building blocks of an argument.

27 more cards in the app