[m-dev.] semantics with any insts

[Ralph Becket]

Peter Schachte, Wednesday, 29 March 2006:
> On Wed, Mar 29, 2006 at 01:26:58PM +1000, Peter Stuckey wrote:
> > An answer in CLP (with any insts) is a set of constraints not known to 
> > be false, and determinism tells you
> > how many sets of constraints you can have.  This is the S semantics for 
> > LP/CLP.
> 
> This doesn't seem very good for Mercury, because it's very
> operational.  For example, is this predicate deterministic:
> 
> 	p(X) :- X =< 4, X >= 2.
> 
> Your semantics distinguishes between {{2=<X, X=<4}} and
> {{X=2},{X=3},{X=4}}

I don't think it does.  As far as I can see, these two constraint sets
are identical.

> But to me the determinism of
> p/1 should indicate how many solutions for X p(X) has.

I've always thought that determinism *was* an operational description.

-- Ralph
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