the mechanism for signatures in RIF

I have an action to come up with a mechanism for specifying signatures
without the need to assign Boolean signatures and arrow signatures to sorts.

Having a closer look at the Core proposal, I realized that the current
proposal is sufficient. In the section "multi-sorted RIF logic" we see
that Boolean and arrow signatures are assigned to symbols from Const. 
This is exactly what we need.

A definition of the signature of a function-free FOL variant of RIF
(let's call this RIF-FOL) might look something like, assuming that the
sort Resource corresponds to the usual abstract domain:

Let URI be the set of URIs.
The set Const \subseteq URI is partitioned into the subsets C, P_0, P_1,
P_2,...
where C is the set of constant symbols (i.e. each c\in C has an arrow
signature Resource), and P_0, P_1, etc. are the sets of nullary, unary,
etc. predicate symbols (each p\in P_i has a Boolean signature Resource^i).


Best, Jos

-- 
Jos de Bruijn,        http://www.debruijn.net/
+43 512 507 6475         jos.debruijn@deri.org
DERI                      http://www.deri.org/
----------------------------------------------
Simple, clear purpose and principles give rise 
to complex and intelligent behavior.  Complex 
rules and regulations give rise to simple and 
stupid behavior.
 - Dee Hock

Received on Wednesday, 21 March 2007 13:25:42 UTC