LSAT Conditional Statements

The If Formula

The part of the statement that is introduced by If constitutes the sufficient condition.

*When is the temporal version of if

*where is the spatial version of if

Ex. If the lake freezes, then the swans will migrate

LF--> SM

The Only If Formula

The part of the statement that is introduced by Only If constitutes the necessary condition.

*Only when is the temporal version of only if

*only where is the spacial version of only if

Ex. Only if you are physically fit can you become a firefighter

BF--> PF

The Only formula

The Only always introduces the a sufficient condition

Ex: The only fruits are apples

F--> A

The All Formula

The part of the statement that is introduced by All constitutes the sufficient condition. The All Formula always applies to statements that being with All.

*The all formula applies to statements that begin with Each, Every and Any.

Ex. All vertebrates have backbones

V--> HB

The No Formula

The statement that is introduced by no constitutes the sufficient condition. The negation of the other part of the statement constitutes the necessary condition. The No Formula always applies to statements that begin with no.

*None applies to the No Formula

No X's are Y's = All X's are not Y's

Ex. No reptiles are warm blooded

R-->WB/

The Unless Formula

The part of the statement that is introduced by unless constitutes the necessary condition. The negation of the other part constitutes the sufficient condition.

***Unless the ness, negate the rest***

Ex. The boat will sink unless we repair the hull.

BS/--> RH

The Not Both Formula

One of the variables (it does not matter which one) constitutes the sufficient condition. The negation of the other variable constitutes the necessary condition.

Ex. Julian cannot be in both London and Paris at the same time

L--> P/

***Remember it is possible for Julian to not be in London or Paris

The Either/ Or Formula

The negation of one of the variables (it doesn't matter which one) constitutes the sufficient condition. The other variable constitutes the necessary condition.

Ex. Either Burgess or Ellis will join the chess club.

E/-->Burgess

***Remember it is possible for Both Burgess and Ellis to join the chess club.

If and Only If

A <-->B

The same goes for

If but only if

When and only when

If then and only then.