Confused about explanations used in conditional logic videos

markkuehling

Hey guys. Newbie here that just signed up on this site a few days ago. I'm confused as to why, when, and how JY is applying the following analogy. Can someone help me understand this?

All beings that are Jedi’s are entities that use the force.
Jedi = Force User

This seems different from:
If Jedi, then Force User.

IF a being IS a Jedi, then the being must be a force user. Isn’t later is a conditional??? And thus not a logical equivalent? Do you see what I’m asking?

If it is the case that:
Jedi = Force User
then it is necessarily the case that:
Force User = Jedi.

But this renders the premise completely not true. Force User also = Sith and Sith (do not equal) Jedi.

I don’t care to pick a debate over about Jedi vs Sith, or Disney vs Lucasfilm. What I’m trying to understand is how equals can be construed as the logical equivalent of a conditional on the LSAT?

Isn't "=" traditionally used as follows?:
Anakin = Darth Vader
Darth Vader = Anakin

Thus "=" functions differently in the form than "->". It is entirely different than saying:

IF Anakin THEN Vader.

Thanks again to anyone who can simplify and clarify! Much appreciated.

lsatcommitted

Hi Mark
Your message is a little confusing. But i will try to help, at least for my own understanding.

Instead of using "=", we should use "->" for "implies"
Example:
All Jedis are force users becomes J->F
the Contrapositive to that is if one does not use the force, one is not a Jedi /F->/J
The Contrapositive is the same logically as the statement above it, it is not the opposite.

Also the Contrapositive should not be confused by saying if one is a Force user, then one is a Jedi F->J, because this is not the case.

At first this kind of logic language is confusing, but its necessary for quick reading of the questions, especially in logic games.

You can try to make an imaginary step between english and the lawgic language by thinking of sets, like you did in elementary school.

A set of all Jedis in a bubble. A set of all Force users in a bubble.
the entire set of Jedis rests inside the bubble of Forces users. if there are more Forces users, then there will be room in the bubble that is not occupied by Jedis. These are the people that Force users, but not Jedis.

Does that make sense?

jdawg113

didnt read all of above post, but what he started with... do not use =... idk if theres really anywhere you would use it, maybe if you're told all jedi use force and all force users are jedi then you could use it but even then I would prob use something else... but either way we werent told the later, therefore we use ->. when we say all jedi use the force, where do you get that jedi=force? its just not there

markkuehling

Ok. I see. Arrow does NOT express an actual equivalent. It expresses an implication. That was not clear in a couple of the videos. But thank you for explaining.

Interesting point Jdawg, I guess we'd use "=" only when we're dealing with number puzzles.

Thanks again.