On Tuesday, February 6, 2018 at 11:44:06 AM UTC-6, Peter Percival wrote:
> peteolcott wrote:
> > On Tuesday, February 6, 2018 at 10:13:05 AM UTC-6, Peter Percival wrote:
> >> peteolcott wrote:
> >>
> >>>
> >>>
https://en.wikipedia.org/wiki/Statement_(logic)
> >>> If the assertion that this expression makes is not provable
> >>> and the negation of this assertion is also not provable then the
> >>> then this expression is not a statement of language because
> >>> it lacks a truth bearer.
> >>
> >> If a theory is weak it may be unable to prove a statement and unable to
> >> prove its negation. A stronger theory may prove one or the other. That
> >> formal provability is relevant to theories is something you
> >> systematically ignore.
> >
> >
> > False(L, X) in formal language L means that there is backward-chaining
> > inference from X to the negation of one or more self-evidently true expressions of L.
>
> The notion of self-evident truths is problematic. What is
> self-evidently true to one person may be self-evidently false to another.
>
All of the existing definitions of this stuff are pretty crappy, that
is why I must start from scratch and rebuild them from the ground up.
Expressions of language L that are defined to have the semantic
property of {True} are simply finite strings assigned to a
specific set: let's come of with a brand new name so there is
no confusion: TRUE_STRINGS(L).
> A more sensible account of falsity *in a formal language* would make
> reference to models.
>
No it is that screwy stuff that confuses people into believing that
there are closed WFF that are neither provable nor refutable.
An expression X of language L is true if there is a proof from
one or more elements Y of TRUE_STRINGS of L to X.
An expression X of language L is false if there is a proof from
the negation of one or more elements Y of TRUE_STRINGS of L to X.
Any closed WFF of L ( ~True(L, X) & ~False(L, X) ) |- Incorrect(X)
Copyright 2018 Pete Olcott