[FOM] negation as a non-primitive logical constant

[Jon Awbrey]

C.S. Peirce frequently used the idea that asserting x => a,
where "a" stands for "any proposition", amounts to denying x.

E.g., see his use of this in connection with Peirce's Law:

http://mywikibiz.com/Peirce%27s_law

Jon Awbrey

Alasdair Urquhart wrote:
> On Thu, 8 Apr 2010, Joao Marcos wrote:
> 
>> I was wondering which are the earliest references to be found in the
>> literature to the "intuitionistic" definition of negation of A in
>> terms of A implying bottom?
>>
>> Joao Marcos
> 
> I don't know the answer to this precise question, but Bertrand Russell
> in the Principles of Mathematics (1903) defines the
> negation of A as (A --> B), where "B" abbreviates
> "for all q, q".

-- 

inquiry list: http://stderr.org/pipermail/inquiry/
mwb: http://www.mywikibiz.com/Directory:Jon_Awbrey
knol: http://knol.google.com/k/-/-/3fkwvf69kridz/1
oeiswiki: http://www.oeis.org/wiki/User:Jon_Awbrey