What is there to get in his approach? His approach is trivial.

"P" is true if, and only if, P.

So he starts from a point in belief which is P is there.

P depends on itself, and the whole thing is evaluated as true.

If it were trivial, would it deserve an entry in the Stanford Encyclopedia of Philosophy?

He discusses a notion of truth in an entirely different context - formal logic/languages. It is certainly not trivial,

let alone circular.

https://en.wikipedia.org/wiki/Semantic_theory_of_truth#Tarski.27s_theory

These are the list of rules they have to come up with to cover that assumption. I need none.

Read 'It is important to note that as Tarski originally formulated it, this theory applies only to formal languages. He gave a number of reasons for not extending his theory to natural languages, including the problem that there is no systematic way of deciding whether a given sentence of a natural language is well-formed, and that a natural language is closed (that is, it can describe the semantic characteristics of its own elements). But Tarski's approach was extended by Davidson into an approach to theories of meaning for natural languages, which involves treating "truth" as a primitive, rather than a defined, concept.'

Yeah you need none. But your argument has no content whatsoever, and therefore is trivial.

Reply: The whole text I have posted is an argument. From top to bottom. How am I not delivering one?

I did not ask for your opinions of me. Ask about any doubts you have on what I wrote.

AND this is important, Ask Politely.

I could be wrong, I could be right. You do not know enough to evaluate that currently.

Talk like a civilized human being. Am I not speaking like one? Where are your manners?

One should not get angry at what is true. It cannot seriously be considered as an argument, exactly because you claim to get something out of nothing (no assumptions at all). You are trying to build a sort of logical analogue of a 'perpetuum mobile'. Of course I know enough to evaluate what you wrote, it requires no sophistication; the flaws are obvious. Even if you had a point, it would be considered to be of no value, because everyone else assumes that it is meaningful to say that something is true (so did Descartes, Tarski, etc indeed any scholar), and thus what you say cannot seriously refute what Descartes, Tarski, etc. said. Your main claim is that 'truth cannot be defined'. Even if this were true, it would be irrelevant: Descartes etc. don't assume that truth can be defined, they just assume that a notion of 'truth' exists (but what this notion is we don't know, we merely assume existence).

I

Set of real numbers is closed ——- True

Set of real numbers is open ——- True

You are making a mistake in defining "open" and "close".

Happens. Both are not simultaneously true in math.

If both were simultaneously true, then under mathematics, they would have no meaning.

What you are essentially saying is A, and it's converse are both true. This breaks math.

Remember there is an important axiom of infinity in math. Definition of "open" and "close" depends on it.

(Dedekind cut, or something which Cauchy has done to establish reals, and poor Russell)

Any other doubts?

It is true that the set of real numbers is closed and open (this is trivial if you look at the definitions). Closed and open are not notions that exclude each other. Sets are not doors (which are either open or closed). Clearly you are not familiar with these notions. The definitions of open and closed do not depend on this axiom. They rely on standard logic, the set-theoretic notions of union, intersection, and complement.