Re: compound propositions

Bob Badour wrote:
> paul c wrote:
>

>> Bob Badour wrote:
>>
>>> paul c wrote:
>>>
>>>> David BL wrote:
>>>> ...
>>>>
>>>>> This boolean valued function can be said to represent a
>>>>> predicate under an interpretation but I'm not sure if that's what you
>>>>> mean.  More specifically, what do you mean by "satisfy" when you say
>>>>> relations satisfy predicates?
>>>>> ...
>>
>> ...
>>
>>>> match the variable names apparent in the predicates and the 
>>>> attribute types are applicable for whatever manipulations (eg., 
>>>> aggregation) the predicate states.
>>>
>>>
>>> In other words, the extension of a predicate is the set of all tuples 
>>> that satisfy the predicate.
>>> ...
>>
>> Yes, but David B asked what 'satisfy' means.

I don't know why the fuss about the word 'satisfy'! Admittedly its casual but some big names use it from time to time. I certainly wasn't trying to alter anybody's vocabulary but I like it because it encourages me to distinguish header from value which helps me think concretely about implementation. I just don't see the usefulness of repetitious acknowledgement that 'it is always true that there is a set of featherless bipeds'. Received on Thu Mar 18 2010 - 19:59:03 CET