Part One, Symbols and Translation: Disjunction

This video on logical disjunction is part of a series I'm working on that aims to teach you, in the simplest way possible, how to do logic.

Category:

Howto & Style

Tags:

• logic
• how
• to
• disjunction
• either
• or
• unless
• compound
• truth
• true
• false

[Monessenite]

I'd like to say that I've enjoyed watching your logic videos. I studied Gensler for logic and was unfamiliar that some of the logic symbols were equivalent. This could have been posted elsewhere, but I do have a specific question on disjunction: Is there a special symbol to denote the "Either p or q?" "p or q but not p and q?" I probably could look on the web, but I'm already here enjoying your videos (and spreading them) and thought I'd ask you instead of finding a source of less credulity.

[azrienoch]

@Monessenite Some notations draw a straight line under or over the disjunction sign to signify that it's exclusive, but it's not necessary, just easier. Just like the biconditional sign isn't necessary. How you would signify exclusivity is (P v Q)^~(P^Q), if you see how that works.

[Iamguerrero]

In the example Either I will die from smoking, or I'll die some other way...

Can the second statement (I'll die some other way) be taken as a form of negation of the first statement ( I will die from smoking) ?

[azrienoch]

It could be, yes. And that's an important point -- translations and how to translate are not always clear.

[sharpie443]

I really wish both of you would learn that cigars are superior to cigarettes. Grate video. My room mate was taking a class that involved truth tables and he eventually droped it because he couldn't understand them. He was kind of an idiot so that doesn't really frighten me away from taking a logic class.

[azrienoch]

Cigars are only allowed while drinking scotch. Glad I could start to give you an introduction. Have you watched the videos on negation and conjunction yet? Those come first, and they make this one make more sense.

[TheZeaf]

ok, im finding this a little more difficult to grasp. If you have either apples or oranges, surely that implies that you cannot have both apples and oranges?

[TheZeaf]

Recently got selected to take part in an experimental critical thinking course my school is running for advanced students... I hope this helps

[ElMajeNica]

¬D, D l= C

[midnightartistry]

Don't die! I like you! lol

[jkgillett]

I've been pausing the vids once there's a translation exercise and trying it to see if I get it. I initially put this down as D or ¬D but then realised that while O is part of ¬D, ¬D is not necessarily part of O (i.e. in ¬D you may not die at all but instead be turned into a pin cushion with self awareness that never dies, this wouldn't be O).

[sonata1992]

You sick bastard you. I love you and you smokiness :P