Skepdick wrote: ↑Tue Jun 16, 2020 11:44 am
PeteOlcott wrote: ↑Tue Jun 16, 2020 3:25 am
If it is true then it is provable.
OK. So is the above "true"? Prove it.
If you can't prove it then it's untrue, right?
∀F ∈ Formal_System
∀X ∈ Language(F)
(((F ⊬ X) ∧ (F ⊬ ¬X)) ↔ Undecidable(F, X))
Gödel says that Undecidable(F, X) means Incomplete(F).
From the sound deductive inference model we can see that this is incorrect. A sound deduction begins with premises that are known to be true and applies truth preserving operations to these premises deriving a conclusion known to be true.
If there is an unprovability break between the premises and conclusion then the conclusion is not derived and the argument is invalid.
If there is an unprovability break between the premises and negation of the conclusion then the negation of the conclusion is not derived and the argument is invalid.
Within the sound deductive inference model Undecidable(F, X)) simply means Invalid(F,X) and when Gödel says that is means Incomplete(F) he is simply wrong.
Copyright 2020 Pete Olcott