Logic 101 (#6): OR/Disjunction

In this lecture, we learn about the "OR" logical operator. When using the logical OR, we mean it as the "inclusive or," which allows for both to be true. If the statement you are trying to translate is an "exclusive or," you need to use different notation. Be careful!

[galvera]

The first youtube class that i have to slow down instead of speeding up

[PunmasterSTP]

I've noticed a fair bit of confusion with disjunction in the inclusive or exclusive sense. I would XOR-t people to always be clear and concise. 😎

But seriously, these videos are solid gold. I'm so glad I found William Spaniel on YouTube!

[wewders]

"Either you can have soup or you can have salad. You can't have both."
You pay for that kind of service? Maybe you should patronize a different restaurant.

[OnlyTruthLove]

one thing I don't understand is why or is used as an and. "will you have soup or salad" should be only an exclusive or, and if you wanted to make it inclusive, you should ask "will you have soup AND salad".... this seems to be much easier.

[CorinthiansVersesthru]

Why do they complicate the issue by making an inclusive or when they could use and?

[Weegee]

Doesn't the xor operator also imply that, beside excluding the true state of variable a if variable b is already true, var a and b cannot be true at the same time, but also cannot be false at the same time (not sure if you mentioned this!).
To clarify, is it not the case that if you're having the steak you won't have the chicken, and vice versa, you cannot have both, BUT ALSO you must pick one of them (the state of not choosing both will output a false!)?
Hope Im making some sense...

[MathCuriousity]

Hey wonderful series - question if I may:

XOR seems pretty intuitive. OR is a bit counterintuitive.
Can we say that OR’s three possibilities are two “XORS” and one “and”? If so, why even have “OR” as a separate thing - going along with your idea of why have y=-x when we can just have -x and make comparisons easier.

Thanks so much!

[ivanthomas]

So how do we know that 'San Deigo is classy or Ron Burgandy is a liar' is an inclusive or and not an exclusive or? Because of the word 'either?' because it seems like one could read it as exclusive.

[Meresortsitar]

Wonder why did they design it like that? Because in real life the exclusive 'or' is much more common than the inclusive one. Why not have a common symbol for that instead? Also... Isn't that actually and/or then?

[TeemoCity]

Why exactly can't I have a super salad?

[chumbo]

This is the only operator that doesn't make sense to me when brought back to english. If I or someone said "I am hungry or I am thirsty" it should mean exactly that, it's either A or B, but not both. Otherwise, how is it different from an AND operator??

[surfistadazona]

This is so different from portugal dude...