# Discrepancy between Classical Logic, Set Theory, Propositional Logic and Languages [closed]

In logic, "Or" strictly refers to logical disjuntion, while "And" strictly refers to logical conjuction.

But in common parlance, both can fill the role of Logical Disjunction

I understand that one should not use logic when talking to people because they may not understand you; but one needs to come clear and context does not always help. One should instead be redundant and repetitive.

When ambiquity arises (i.e. context does not help), how can you know what the person meant if you are unable to ask them to clarify it (e.g. it's written material, the person refuses to explain as they think logic is illogical and nonsense and that what they said was obvious, or any other reason)?

• You can't know, under those circumstances. That's the point of ambiguity. Language is not logic, and it does not always work. Neither does logic. We just have to do the best we can. – jlawler Oct 12 '19 at 22:27
• @jlawler That is the whole point. Solving the problem that is ambiguity. – George Ntoulos Oct 12 '19 at 22:45
• It's not a problem so much as it is a feature. Ambiguity can't be "solved", or even avoided, any more than entropy or gravity can. One can solve individual problems involving ambiguity; but there is no general solution. Understanding requires interpretation and presupposition by both speaker and addressee, and there is no correlation between them, except in individual cases. – jlawler Oct 13 '19 at 17:49
• "... but not concurrently both." as far as I can tell or means xor or and. of course that hinges on your definition of or. get it? – vectory Oct 17 '19 at 15:15
• @vectory Or does not mean And. en.wikipedia.org/wiki/Logical_conjunction en.wikipedia.org/wiki/Exclusive_or en.wikipedia.org/wiki/Logical_disjunction look at the Venn diagramms. My problem is that both Or and And can be used to mean Logical Disjunction. Each has a distinct function but both can fill the role of Logical Disjuntion. – George Ntoulos Oct 17 '19 at 15:26