Re: Constraints explained

Michael Kifer wrote:
>> My understanding is that derivation rules and integrity constraints are
>> just a bifurcation of Horn rules (or sometimes the two halves of
>> something beyond Horn).  As such they fit easily into the same
>> semantics.
>>
>>    - sandro
>>     
>
> Depends what you call "semantics". They have the same first-order
> semantics in the sense that if you give me a first-order interpretation
> then the definition of what it means for each such rule to hold in that
> interpretation is the same in both cases.
>
> But Horn-rules-as-constraints are reasoned with differently from
> Horn-rules-as-derivation-rules.
>   
I agree.
>
> I suppose that this is what Francois wanted to convey when he proposed
> annotating rules with reasoning methods, 
This is what I wanted to convey.

Thanks, Michael, for making the point!

Francois

PS: I do not follow you in the non-FOL of ICs...