Re: Joint Committee telecon tomorrow 4 November

From: Benjamin Grosof (
Date: 11/04/03

  • Next message: Ian Horrocks: "Re: Joint Committee telecon tomorrow 4 November"
    At 05:26 PM 11/4/2003 -0600, pat hayes wrote:
    >Suggestion, following Ben's reporting of Tim's observation. The ideas that 
    >(1) an empty consequent is 'false' and (2) that a consequent is a 
    >conjunction, are in opposition. The former arises historically from 
    >thinking of a rule as an implication or a sequent, where a compound 
    >consequent would be considered a disjunction.  I think this is a 
    >fundamental snag in the current proposal ( sorry I didnt notice it before) 
    >and suggest that we change the basic rule syntax slightly so that 
    >consequents are atomic, not conjunctive, but then allow the present case 
    >as a Lloyd-Topor style syntactic sugar for a conjunction of rules. This 
    >changes the presentation slightly but makes it natural for an empty 
    >consequent to be considered a missing atom - false - rather than an empty 
    >conjunction - true. It also simplifies the semantics, and makes the 
    >Lloyd-Topor mapping work properly in all cases.
    this is fine by me as a way to define things.  6 of one, half dozen of 
    another.  the main point is to make sure we explicitly define the case of 
    empty head to mean false, rather than just say something like "the head is 
    a possibly-empty conjunction of atoms".
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