~A unless P or Q

Rev_Lefe

Hi, I was threw off by this logic line as title.
My grammatical understanding is when using "not A or B", the sentence sometimes mean not A and not B.
If a sentence uses "not A or not B", then it means literally "not A or not B".

However, when seeing a sentence "unless A or B", I am not sure how to interpret such sentence.
So I wanna know which is the correct translation of the title?
(i) not A if neither P nor Q
(ii) not A if not P or not Q

Thank you for your time.

Appreciatively,
Leon

Alexsplainlater

Both i and ii technically.

"A" will not occur without the presence of "P," "Q,"or both simultaneously.

FaviPapi-1-1

It's the first one: (i)

If you are having trouble diagraming it, then perhaps you can negate the sufficient part, which would be the portion before the word "unless," rather than taking the word "unless" to mean "if not"...

In other words:

"~A unless P or Q"

1. Negating the sufficient part, which we take to be everything before the word "unless":

If A --> P or Q

1. Taking the word "unless" to mean "if not":

~P + ~Q --> ~A

1 and 2 are equivalent; one is the contrapositive of the other and vice versa