In the same way that not all finite strings are well-formed
formula (when semantic criteria is applied) not all closed
WFF are logic sentences.
Any expression of language that is neither true nor false is
not a logic sentence of any formal system that has been
adapted to conform to the sound deductive inference model.
Logic sentences are always derived from sound deduction. In
the sound deductive inference model this means that there is:
[a connected sequence of valid deductions from true premises to a true conclusion].
When axioms are construed as expressions of language having the
semantic property of Boolean true then the theorem consequences
of formal proofs form:
[a connected sequence of inference from axioms to a true consequence].
In neither case is undecidability, incompleteness or inconsistency possible.
Eliminating Undecidability and Incompleteness in Formal Systems
https://www.researchgate.net/publication/332427635_Eliminating_Undecidability_and_Incompleteness_in_Formal_Systems
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Copyright 2019 Pete Olcott All rights reserved
"Great spirits have always encountered violent
opposition from mediocre minds." Albert Einstein