Re: A statement on dbdebunk.
Date: Mon, 21 Aug 2006 21:13:28 GMT
Message-ID: <YlpGg.57038$pu3.630359_at_ursa-nb00s0.nbnet.nb.ca>
kvnkrkptrck_at_gmail.com wrote:
> Keith H Duggar wrote: >
>>Erwin wrote:
>>
>>>"My material is sound because unlike all the stuff
>>>floating in the industry, the logical level is formal and
>>>the conceptual level was developed to allow 1:1 mapping to
>>>it.
>>>
>>>Conceptual model: informal business concepts
>>>(enterprise-specific)
>>>
>>>Logical model: formal representation (as much semantics as
>>>a system is capable of "understanding")
>>>(enterprise-specific)"
>>>
>>>Conceptual model === INFORMAL
>>>Logical model === FORMAL
>>>Conceptual model "ALLOWS A 1:1 MAPPING" to the logical
>>>model
>>
>>Note also that "as much semantics as a sytems is capable of
>>'understanding'". That confirms that
>>
>>>Now, it seems to me that "allows a 1:1 mapping" means that
>>>there is some kind of isomorphism between the things that
>>>are mapped in such way.
>>
>>He did not mean (nor did he state) isomorphism. He stated
>>the mapping is 1:1. Remember that isomorphism is 1:1 /and
>>ONTO/. The mapping is not onto. He seems to say that there
>>are conceptual elements that are not mapped to the logical
>>model.
> > Shouldn't that be, "He seems to say that there logical elements to > which no conceptual elements map."?
No. He had it right.
>>>And the fact that some kind of isomorphism between two
>>>things can be found, implies that any quality or property
>>>that holds/exists/is proven for either of the things
>>>mapped, necessarily also holds/exists for the other thing
>>>mapped.
>>>
>>>So if model X has the property of being formal in some
>>>sense, and model Y is in some way isomorphic to model X,
>>>then it necessarily follows that model Y is also formal in
>>>that same sense as model X is formal .
>>>
>>>So the statements quoted here, seem contradictory to me,
>>>if not quackery.
>>>
>>>Anyone care to correct me on this, or comment in any other
>>>way?
>>
>>You assumed isomorphism and reached a contradiction. Your
>>premise was simply false. At least it appears so given the
>>excerpt.
>>
>>Does this clear it up or am I missing something too?
>>
>>-- Keith -- Fraud 6
>
> To (hopefully) clarify: Consider the set of conceptual elements C =
> {C1, C2, C3} and logical elements L = {L1, L2, L3, L4}. The following
> mapping from C to L is a 1-to-1 mapping:
> {C1, L1}, {C2, L2}, {C3, L4}
> yet, it is not ONTO and certainly doesn't establish isomorphism.
Except that formal logic is a subset of what man conceives. Received on Mon Aug 21 2006 - 23:13:28 CEST