Its only proven as long as "There are some lemons that are not yellow" is not introduced. — Philosophim
What do you mean "introduced"?
Are you saying there is a second round of axiomatic systems where we introduce more axioms?
The very strong impression I get is that you have an intuition about what is true and you are trying to fit that intuition into systems without understanding the intuition yourself let alone communicating it to others.
I can't see the argument you are making. What I see is:
"Yes, Yes, but when we introduce stuff then something."
Since I've seen you understand and use effective arguments, this non-statement tells me that your prejudices have come up against a set of facts that don't fit. In a panic, you are re-iterating your prejudices rather than forming an argument which would require examining those prejudices against the new evidence; a process that you can already see will be deeply uncomfortable for your prejudices.
I'm not accusing you of anything nefarious. This is a natural (and usually unconscious) mechanism.
As a rule, people will try every possible alternative before examining and changing their prejudices. If there is a chance that shouting loudly "OVER THERE!" will work then you (or your subconscious) will give it the good old college try before taking the risk of learning and developing.
Learning is painful enough without some dick saying "Look! Over here! This person is learning!"
I could, of course, be reading too much into a post that forgot to bring the argument.
Segue...
Learning and argument in the absence of Logic
Since Axiomatic Mathematics has been hoisted by its own petard in the form of The Principle of Explosion; and informal logic bears only a passing resemblance to the now defunct formal logic; how can we best understand the processes of learning and argument?
A story of survival
The trick to surviving is being good at survival.
The newly born mammal that instinctively seeks its mother's milk has a better chance of passing on its genes than one that doesn't.
The foal that can stand and run within hours of birth has a greater chance of evading predators than one that takes months to stand up.
Having a genetic instinct can be a great aid to survival, but developing such an instinct takes many, many generations.
Mimicry
The parents of a baby have survived long enough to have a baby. If the baby mimics the behaviour of the parents it is taking on behaviours which have already been shown to be successful.
When you started to learn your native language you started by mimicking the sounds and shapes.
As the process continues the depth increases. Each mimicked behaviour is associated with events. We only do the "poo poo" mimic when we have a particular feeling.
When you first started learning to multiply and divide you didn't have an innate understanding of the Set Theoretic derivation of natural numbers. You just followed a particular pattern of behaviours that everyone agreed was the right pattern in that circumstance.
Calculus is just a matter of learning and following a particular set of steps in a particular set of situations.
Consequences of Mimicry, learning
Learning through mimicry is fast. One of the great strengths of humans is their ability to absorb a large number of different behaviours in a short time and, as a rule, present those behaviours at the right time.
It isn't practical for everyone to analyse each new piece of information, weigh all the competing theories and come to an objective conclusion based on the evidence. If you had to build everything from first principles working from Plato through to Russell before you could accept what the math teacher is telling you we'd still be flinging excreta at each other.
Just learn the behaviour, learn the rules for when to apply it. Done. Maybe later we'll refine the behaviour and the rules but all you have to do in this moment is memorise and apply.
A downside of mimicry is that conformity is king. Accurate and appropriate application of mimicked behaviours is (or was) a matter of life or death. The wrong ritual meant the hunt failed, or the crops failed, or the bed was within reach of the bear.
Complex Mimicry
A set of behaviours and the rules about when to apply them can be arbitrarily complex. Circumstances can overlap such that multiple behaviours are applicable with sophisticated rules about which take precedence or how to combine behaviours.
Nor is mimicry static. We refine and improve based on our experiences.
Knowledge
This story about mimicry has one particular feature I'd like to underline: Logic isn't necessary.
The initial justification for mimicked behaviours was that the person being copied had lived long enough for you to come along and copy them.
Survival of the fittest applied to behaviours. (quick shoutout to Richard Dawkins' 'Memes').
A cat learns what behaviours result in food, or scritches, or being left the hell alone.
Animals are able to learn and adapt to situations without the use of formal logic.
Humans can, arguably, learn more behaviours with a greater depth of complexity for when and where to apply them but that is a difference of degree, not of kind.
The tale of the Pacific Cargo Cults
Some Pacific Islanders would make hats and gesticulate at the sky in the hope of bounty from the heavens.
During World War II, American supply bases were setup on remote Pacific islands. Planes would be guided in using radio headsets and semaphore. The planes often carried food and other luxuries.
When the American's departed the islanders tried to call down fresh bounty by mimicking the ground crew. They didn't know that essential parts of the ritual included very specific hats and membership of the United States of America Armed Forces.
Phones
The majority of people happily use a mobile phone to call up that funny video without knowing how one works.
Physicists can plug values into formulas, perform the appropriate rituals and extract useful results. But any physicist who claims to fully understand General Relativity or Quantum Mechanics is stretching the truth.
If you've ever met an accountant, or worse, an economist you will know that they confidently perform the prescribed tasks with little comprehension of the tools and processes.
Recent research has found that Depression is not due to serotonin or dopamine deficiencies. No one knows why anti-depressants work.
The whole history of medicine is rituals that at least a few people survived so they kept doing them to the next victim.
The mechanism of Axiomatic Mathematics is a ritual: Follow these deterministic steps. (Did you know, computer programs are axiomatic systems. They start with an initial condition and then iterate those conditions using a set of rules. (This isn't me being quirky about where I apply definitions - Computational axiomatic mathematics is an entire thing)).
Thoughts
My thoughts consist of networks of relationships. These networks have shapes
I compare shapes in my mind. Some shapes mesh together well. These seem true, valid, justified to me.
Some shapes are discordant. Their existence distorts and corrupts other shapes until it is barely possible to recognise what those shapes signify. These indicate a faulty relationship. One or more of my internal relationships is incorrect.
Fixing the networks when a fault has been identified can be laborious. It largely comes down to a matter of trial and error of changing relationships until they once more form a harmonious result.
Discordant
An axiomatic system is in error if it produces contradictions. Networks of relationships are in error if they are discordant.
I think these two descriptions share a common observation.
We have a case of "I know it when I see it" that is really hard to pin down without running into trouble. In the case of axiomatic mathematics, as soon as you define what a contradiction is, you have proven everything to be inconsistent.
Now, imagine a network of relationships. Imagine every possible network of relationships. Can you see them?
Notice how one network does not preclude another?
In principle, you can have every possible network of relationships in your mind at the same time (I'm sure you have a large mind).
Networks of relationships do not contradict each other simply through the nature of their shape.
If we find some concepts to be discordant with each other it is not due simply to their physical form.
We could beat around the bushes, but the significant determinant is you.
Without you
Without you there is no meaning, no significance, no discord.
A tiger crouching in the bushes is just a shape in the universe; no more, or less, significant than any other shape... until you give that shape significance. You walking past that bush gives the shape significance. You determine how you respond to the networks of relationships that you perceive around you (and within you).
If you abstract away your existence there is nothing left.
You need to exist to perceive. You need to exist to think. You need to exist to argue.
Your existence is the foundation of your perceptual universe.
Trying to make statements as if you don't exist is futile. If you don't exist you can't make statements. If you don't exist you can't decide what is meaningful.
Summary
Everything is relationships.
Among these relationships is the relationship between your existence and everything you do and experience.
If you try to sever this relationship, you cease to exist.