Whats the evidence that evidence-proves propositions to be either true or false?

Wheres the evidence for evidentialism?Whats the evidence that evidence-proves propositions to be either true or false?
Some propositions are self-evidently wrong: ';Dogs have 5 legs.'; ';Bush was our first President.'; Experience tells us it is wrong.





Other props. must be researched for truth: ';Arianism won out at the Council of Nicaea.'; Wrong.





A proposition is only one part of a ';syllogism.'; A syllogism is 3 propositions. 2 of them state the case; the third is the conclusion.





Syllogisms have 2 ';terms,'; which are the points trying to be made by the syllogism. They are the ';major'; and the ';minor.'; There is a ';middle'; term which never appears in the conclusion.





That fact is one of the pieces of 'evidence.' If the minor appears in the conclusion, you've written the syllogism incorrectly, so the whole thing is invalid.





2 negative propositions cannot create a conclusion


From 2 ';particular'; props, no conclusion can be formed.





There are so many rules, I still have to consult my notes when I run into problems.





But the ';evidence'; is in the formality of the way the syllogism is put together.





Look at the 2nd link to see the difficulty of logic.Whats the evidence that evidence-proves propositions to be either true or false?
Evidence defines itself in the moment.





For example, lets say you walk in to your kitchen, and you are unsure whether you meal is cooked. You open the oven, and you find it is finished. That is evidence that your meal is finished.





Now what's the evidence that that evidence is ';evidence';? By definition evidence is what you observe to be true, verifiable, and repeatable. Therefore, since you've observed it to be true, verifiable, and it didn't change, then it is evidence for its evidence.
It's called Existence. If at least one solution can be determined for a given problem, a solution to that problem is said to exist. Frequently, mathematicians seek to prove the existence of solutions (by means of a so-called existence theorem) and then investigate their uniqueness (by means of a so-called uniqueness theorem). If one solution is known to exist but it is not known how many total solutions may exist, it is common to say that there is known to be at least one solution.





There are many other such evidences: At least one, Exactly one, Iff, Precisely unless, XNOR, XOR, Implies, Necessary, Sufficient.





All-deep-Math-Logic stuff!0!





Good luck!