:OK:




Kennethamy probably knows more logic than I do. I'm only 20.

Knowledge of logic is not a function of age. Frank P. Ramsey, who knew more logic than both of us put together, times 10, died at the age of 26.

Frank P. Ramsey - Wikipedia, the free encyclopedia

A not B then AB ...

To negate, the proponents recognize each other presence, and assimilate...

Regards>FILIPE DE ALBUQUERQUE

Your answer to what? This is a question about formal logic, because it is in formal logic that a false proposition implies any proposition. So how can an answer not have anything to do with formal logic?

Sorry, I was referring to myself, i did not study Logic, so I am stating only an informal opinion...but I would like to know what you or someone else think of it.

Regards>FILIPE DE ALBUQUERQUE

Your answer to what? This is a question about formal logic, because it is in formal logic that a false proposition implies any proposition. So how can an answer not have anything to do with formal logic?

Doesn't that rely on Disjunctive Syllogism or Reductio Ad Absurdum?

Actually, I think it is just the converse. DS, and RAA rely on F>X. But is that what you are asking?

Typically, it goes like this:

Sorry, I don't know what you are getting at. Could you be more explicit?

I guess I don't understand what you mean by "relies". Do you mean that F>X implies DS or RAA? How?

Actually, I think it is just the converse. DS, and RAA rely on F>X. But is that what you are asking?

Doesn't that rely on Disjunctive Syllogism or Reductio Ad Absurdum?

No it does not. Logical implication is defined in a way such that it directly follows from the definition. With the possible worlds' approach it is defined something like this:
[INDENT]P implies Q iff there is no possible world where it is not the case that Q and it is the case that P.

[/INDENT]Obviously if there is no possible world where P is the case, then there is no possible world where P is the case and Q is not the case.

Right. And then the other lines on the truth-table have to conform with, TF F, including that a false proposition (materially) implies any proposition.

What do you mean? I don't understand the sentence about truth tables and TF F.

I agree that a false proposition logically implies any proposition. I also agree that a false proposition materially implies any proposition. This is logically implied by the former.

Where did I say that? Are you all right?

Two posts up. You know. I quoted you.