Re: A Logical Model for Lists as Relations
From: Bob Badour <bbadour_at_pei.sympatico.ca>
Date: Fri, 12 May 2006 04:10:55 GMT
Message-ID: <jVT8g.6608$A26.169218_at_ursa-nb00s0.nbnet.nb.ca>
>> Jay Dee wrote:
>>
>>> Bob Badour wrote:
>>>
>>>> Jay Dee wrote:
>>>>
>>>>
>>>>> vc wrote:
>>>>>
>>>>>
>>>>>> Jay Dee wrote:
>>>>>>
>>>
>>>>> >> What's 'bunch theory' ?
>>>>>
>>>>> As for my own: scalars are boolean, numbers, and characters. Data
>>>>> may be structured (Here we go down the rabbit hole!) as:
>>>>> a bunch (unpackaged and unindexed),
>>>>> a set (packaged and unindexed),
>>>>> a string (unpackaged and indexed), and
>>>>> a list (packaged and indexed).
>>>>>
>>>>> More terminology? Well, bunches and sets consist of elements, which
>>>>> has the meaning we're familiar with from sets. Sets are sets; they
>>>>> are a package of elements constructed with {} operator. , (comma)
>>>>> is the set union operator. Unpackaging a set - interpolating the
>>>>> contents of a set - yields a bunch, which also has a comma union
>>>>> operator. So
>>>>> a, b, c is a bunch
>>>>> {a, b, c} is a set.
>>>>>
>>>>> The empty bunch is null and the empty set is {null}.
>>>>
>>>> I strongly suggest you avoid this use of null here, because it in no
>>>> way
>>>> resembles the null used elsewhere in database theory.
>>>
>>>> Frankly, other than seemingly unimportant punctuation, I see no
>>>> difference between your set and your bunch. Is there an operational
>>>> difference?
>>>
>>> The whole point is that {} and , aren't punctuation; they're
>>> operators.
>>
>> What's the operator ?
>
> The braces and the comma are operators.
Date: Fri, 12 May 2006 04:10:55 GMT
Message-ID: <jVT8g.6608$A26.169218_at_ursa-nb00s0.nbnet.nb.ca>
Jay Dee wrote:
> vc wrote: >
>> Jay Dee wrote:
>>
>>> Bob Badour wrote:
>>>
>>>> Jay Dee wrote:
>>>>
>>>>
>>>>> vc wrote:
>>>>>
>>>>>
>>>>>> Jay Dee wrote:
>>>>>>
>>>
>>>>> >> What's 'bunch theory' ?
>>>>>
>>>>> As for my own: scalars are boolean, numbers, and characters. Data
>>>>> may be structured (Here we go down the rabbit hole!) as:
>>>>> a bunch (unpackaged and unindexed),
>>>>> a set (packaged and unindexed),
>>>>> a string (unpackaged and indexed), and
>>>>> a list (packaged and indexed).
>>>>>
>>>>> More terminology? Well, bunches and sets consist of elements, which
>>>>> has the meaning we're familiar with from sets. Sets are sets; they
>>>>> are a package of elements constructed with {} operator. , (comma)
>>>>> is the set union operator. Unpackaging a set - interpolating the
>>>>> contents of a set - yields a bunch, which also has a comma union
>>>>> operator. So
>>>>> a, b, c is a bunch
>>>>> {a, b, c} is a set.
>>>>>
>>>>> The empty bunch is null and the empty set is {null}.
>>>>
>>>> I strongly suggest you avoid this use of null here, because it in no
>>>> way
>>>> resembles the null used elsewhere in database theory.
>>>
>>>> Frankly, other than seemingly unimportant punctuation, I see no
>>>> difference between your set and your bunch. Is there an operational
>>>> difference?
>>>
>>> The whole point is that {} and , aren't punctuation; they're
>>> operators.
>>
>> What's the operator ?
>
> The braces and the comma are operators.
An operator is just a symbol. Saying a symbol is an operator conveys absolutely no information whatsoever.
>>> Well, it's not my invention -- and I'm not arguing that this is a
>>> notation that everyone should embrace. Part of the point is that
>>> we're stumbling on each other's words.
I think that's solely your problem. Nobody else seems to have any difficulty. Received on Fri May 12 2006 - 06:10:55 CEST