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Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V34 (Logical implication ERROR)

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olcott <NoOne@NoWhere.com> writes:
> On 7/24/2020 5:47 PM, Keith Thompson wrote:
>> olcott <NoOne@NoWhere.com> writes:
>>> Logical implication
>>>      p  q  p ⇒ q
>>> (a) T  T    T
>>> (b) T  F    F
>>> (c) F  T    T
>>> (d) F  F    T
>>>
>>> p = "I will go to the store"
>>> q = "I will buy eggs at the store"
>>>
>>> (a) I will go to the store and buy eggs while I am there is true
>>> (b) I will go to the store and not buy eggs while I am there is false
>>> (c) I will not go to the store and buy eggs while I am there is true
>>> (d) I will not go to the store and not buy eggs while I am there is true
>>>
>>> (c) I will not go to the store and buy eggs while I am there is true
>>> Proves that Logical implication derives incorrect consequences
>>
>> No, it doesn't.  (c) just means if it were the case that you don't go to
>> the the store *and* you buy eggs at the store, p ⇒ q is still true.  The
>> fact that that's not possible 
>
> You can't buy egqs AT THE STORE remotely

If you were born at the store, then you don't have to go to the store to
buy eggs there.

> (unless you buy eggs remotely? or maybe
>> you were born at the store?) doesn't make the conclusion invalid,
>> because that's what "p ⇒ q" *means*.
>
> Then "p ⇒ q" is a fricking God damned liar thus proving that symbolic
> logic is broken.

Dude, calm down.

"p ⇒ q" does not say or imply that it's possible for p to be false while
q is true, nor does it say or imply that it's not possible.

All "p ⇒ q" says is that *either*:
    p is true and q is true
    *or*
    p is false and q is true
    *or*
    p is false and q is false
*but*
    it is not the case that p is true and q is false

There may well be other reasons why one or more of those three
cases might not be possible.

"p ⇒ q" means "not (p and not q)".  That's *all* it means.  It doesn't
carry the implication of causation that the English if/then construct
sometimes does.  Is "not (p and not q)" a "fricking God damned liar"?

[...]

-- 
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
Working, but not speaking, for Philips Healthcare
void Void(void) { Void(); } /* The recursive call of the void */

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Simply defining Gödel Incompleteness and Tarski Undefinability away V34 (Logical implication ERROR) olcott <NoOne@NoWhere.com> - 2020-07-24 17:26 -0500
  Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V34 (Logical implication ERROR) David Kleinecke <dkleinecke@gmail.com> - 2020-07-24 15:45 -0700
    Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V34 (Logical implication ERROR) olcott <NoOne@NoWhere.com> - 2020-07-24 17:53 -0500
      Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V34 (Logical implication ERROR) Kaz Kylheku <793-849-0957@kylheku.com> - 2020-07-24 23:55 +0000
  Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V34 (Logical implication ERROR) Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-07-24 15:47 -0700
    Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V34 (Logical implication ERROR) olcott <NoOne@NoWhere.com> - 2020-07-24 17:57 -0500
      Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V34 (Logical implication ERROR) Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-07-24 16:19 -0700
        Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V34 (Logical implication ERROR) olcott <NoOne@NoWhere.com> - 2020-07-24 19:20 -0500
          Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V34 (Logical implication ERROR) Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-07-24 18:29 -0700
            Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V34 (Logical implication ERROR) olcott <NoOne@NoWhere.com> - 2020-07-25 23:14 -0500
              Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V34 (Logical implication ERROR) André G. Isaak <agisaak@gm.invalid> - 2020-07-25 23:13 -0600
      Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V34 (Logical implication ERROR) Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-07-25 00:34 +0100
        Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V34 (Logical implication ERROR) olcott <NoOne@NoWhere.com> - 2020-07-24 19:51 -0500
          Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V34 (Logical implication ERROR) André G. Isaak <agisaak@gm.invalid> - 2020-07-24 19:29 -0600
            Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V34 (Logical implication ERROR) olcott <NoOne@NoWhere.com> - 2020-07-25 23:04 -0500
              Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V34 (Logical implication ERROR) André G. Isaak <agisaak@gm.invalid> - 2020-07-25 23:05 -0600
          Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V34 (Logical implication ERROR) Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-07-25 02:39 +0100

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