Logics handbook

[Rodion Romanovich]

You are either missing a parenthesis or having one in excess.

Thanks!

I was of the belief that quantifiers: A and E (inverted) was used only in predicate logic, not in formal logic.

The operators used in traditional formal logic, to my knowledge is: ^, v, -->, <--> and L (not). Only those.

You are correct. The quantifiers were introduced early as a peek of what would come in chapter 2 (which is about predicate logic).

In my course we called those contingent statements. So we have, contradictions, tautologies and contingent statements.

Thanks!

Maybe you should stress the fact, that the nature of the argument is considered as the form, not substance. So, it doesn't matter what P,Q,R,S etc. equates to, as long as the form is valid you have a sound/valid argument.

Yes, I'll look into this later, it will require a careful phrasing and I must think through where to put it, but it is, of course, something that I should stress.