Re: William T. Parry gets rid of Disjunction introduction

On 03/07/2026 17:46, olcott wrote:
> On 7/3/2026 3:17 AM, Mikko wrote:
>> On 02/07/2026 17:37, olcott wrote:
>>>
>>> x = "The Moon is made from green cheese"
>>> y = "Donald Trump is the one and only Lord and Savior Jesus Christ:
>>> POE concludes (x ∧ ¬x) ⊢ y
>>>
>>> "the principle of explosion is the theorem according to
>>>   which any statement can be proven from a contradiction"
>>> https://en.wikipedia.org/wiki/Principle_of_explosion
>>>
>>> When you pay attention to the meaning of the words
>>> and correctly apply correct semantic entailment on
>>> the basis of the meaning of those words then the
>>> principle of explosion is a PSYCHOTIC BREAK FROM REALITY.
>>
>> No, it is not. The premise x above is a break from reality. But that
>> is not in logic, it was introduced by you. Even without the principle
>> of explosion it is possible to infer a false conclusion from a false
>> premise. 
> 
> Yes. From "I am 35 feet tall" ⊢ "I am 35 feet tall"
> and as you said my premise is literally FALSE
> (P ∧ ~P) ⊢ FALSE
> 
>> The principle of explosion merely facilitates tinding a
>> conclusion that is so obviously false that it convincingly proves
>> that the remise is false. 
> 
> There is nothing semantically relevant that can be
> proven from a contradiction besides bare FALSE and
> bare FALSE only entails bare FALSE.

Yes, there is. From the contradiction "I have blue eyes and
I don't have blue eyes" one can prove "I have blue eyes" and
"I don't have blue eyes", both of which are semantically
relevant, and one of which in addition is false.

-- 
Mikko