[Attempto] AceRules help regarding generalized quantifiers

[Tobias Kuhn]

Hi Stephan,

Such generalized quantifiers are not interpreted by AceRules. "exactly 2" is accepted, but there is 
no relation to "at least 2" or "less than 5" for AceRules. This is because the underlying rule 
formalisms do not support such cardinality statements. It might be that there are extensions thereof 
that would support such things. I am not really up to date. I haven't been working on such rule 
problems recently.

What you have to consider is that the forward-chaining approach may easily break if such cardinality 
statement are processed in some way. Your statement "John has exactly 2 orders" should also imply

   John has less than 3 orders.
   John has less than 4 orders.
   John has less than 10 orders.

... and so on. Thus, you get an infinite answer set and the rule engine won't terminate.

In case you want to change AceRules to handle such things in one way or another, have a look at the 
file "courteous_interpreter/answerset_generator.pl" of the AceRules source code.

For the list: a pre-release of the AceRules source code can be downloaded here:

   http://attempto.ifi.uzh.ch/site/downloads/files/acerules-081124_unofficial.zip


Cheers,
Tobias



Stephan Mueller wrote:
> Hello,
> 
> I've been using AceRules trying to put together a small set of ACE
> rules and execute them in courteous mode. However, I do have a problem
> with generalized quantifiers, as it is illustrated in the following
> example:
> 
> Input: "If someone X has at least 1 order then X is a customer. John
> has exactly 2 orders."
> 
> Output: "John has exactly 2 orders."
> 
> In this example, I would additionally expect the output "John is a
> customer" which I only get when not using the generalized quantifiers
> and specifying the exact amount of orders ("If someone X has 2 orders
> then X is a customer. John has 2 orders.")
> 
> Are these constructs not supported in AceRules or is there another way
> to formulated rules involving quantities? Any help is appreciated.
> 
> Thanks,
> Stephan
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