[Attempto] or is interpreted as inclusive or , or xor?

[Norbert E. Fuchs]

On 11 Jul 2010, at 09:47, Gabriele Kahlout wrote:

> 2010/7/11 Norbert E. Fuchs <fuchs at ifi.uzh.ch>
> 
> ...
> Not in our experience. We checked naturally occurring "either-or" on the web, and found that in most cases it did not mean exclusive or, but emphasis.
> 
> That's interesting, is there a report on this research?

No, this was done informally quite a number of years ago. In the end, we decided not to have an explicit construct for the exclusive or in ACE.

> ...
> 
> So in this case one should have written "the customer inserts a VisaCard or inserts a MasterCard, and not both and inserts a code.
> But there is no support for both, so how could mutual exclusiveness be expressed?

> "No card is inserted while another card is inserted. The customer inserts a VisaCard or inserts a MasterCard, and inserts a code."
> but function words while and another don't exist. So:
> "If a card is inserted then no other card is inserted. ..."
> but other also doesn't exist:
> "If a card X1 is inserted then no card is inserted except X1. ..."
> but except doesn't exist:
> "If a card X1 is inserted then exactly X1 is inserted. ..."
> exactly meaning that no other card is inserted.
> 
> Is the last the most natural way to express xor in ACE for the example sentence?

No. Note that an exclusive or could be imbedded in an if-then sentence which would make your constructs very hard to read.

To express "A XOR B" in ACE you write – as you do in standard FOL – "(A and not B) or (B and not A), similar to what you did  in your email of 10 July 2010 22:10:10 CEST.  

Or – and this is probably an exclusive or – you could add the exclusive or to ACE, download the Attempto Parsing Engine APE and extend it by grammar rules processing the exclusive or.

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What does this mean?

   --- nef