Re: [boost] Re: is_base_and_derived question

From: David Abrahams (dave_at_[hidden])
Date: 2003-01-31 11:31:17

Terje Slettebø <tslettebo_at_[hidden]> writes:

> No. You can't prove a negative, an impossibility. 

I think that's wrong, and here's my one white crow to prove it ;-)

I can prove that there can never exist a positive integral multiple of 2 which
is both greater than 2 and prime.  

It's the same as saying that *every* positive integral multiple of 2
which is greater than 2 is a non-prime (now it's not a negative
statement anymore, but it is logically equivalent).  The positive
integral multiples of 2 which are not greater than 2 are: 2.  Since
every other positive integral multiple of 2 is divisible by both 2 and
itself, it must be non-prime.  QED, or whatever it is you say while
gleefully dancing on the logical grave of your vanquished opponent
<wink>.

But anyway, isn't this straying a little bit far from being on-topic?

-- 
                       David Abrahams
   dave_at_[hidden] * http://www.boost-consulting.com
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