Re: comments on current version BLD document: symbols, datatypes, semantics

Michael Kifer wrote:

>> 2- section "signatures and a condition language of RIF^BLD^": the
>> definition of equality atoms is not entirely clear: the symbol = is not
>> a constant symbol in RIF, according to the syntax definition in section
>> "presentation syntax" (it does not have the symbol space).  Furthermore,
>> as it is correctly mentioned that equality is not a built-in predicates,
>> I feel there is an impedance mismatch between this predicate symbol and
>> all other kinds of predicate symbols.  Finally, equality is currently
>> not mentioned when atomic formulas are initially defined.  Therefore, I
>> would propose to define equality atoms a=b directly when first defining
>> atomic formulas.
> 
> A good point! You were looking at a version before I moved = further down,
> but the point about its symbol space is well-taken. It should be either
> rif:local (my pref) or rif:iri.
> 
> I experimented with requiring all symbols to have explicit symbol spaces in
> the examples, but I think they become unsightly due to that. Perhaps we
> should not require ^^rif:local explicitly. Then we could write a=b as
> before.  If people think that we should insist on explicit symbol space
> names (as it is done now, to make the syntax look more abstract and devoid
> of syntactic sugar) then I am fine with writing a =^^rif:local b or even
> equal^^rif:local(a,b).
> 

I would prefer to drop explicit ^^rif:local.
Otherwise, the presentation syntax becomes really difficult to read.

Regards,
Igor