[mercury-users] Solver types and \=

Peter Schachte schachte at cs.mu.OZ.AU
Fri Aug 12 12:55:29 AEST 2005

> > Perhaps it would be better to leave '\=' undefined for solver types,
> > and leave the user to define a custom inequality predicate if it makes
> > sense?
> Hmm, that sounds horribly warty to me.  Unfortunately, I think this is
> one of those situations where there is friction between Mercury's
> execution model and the use of solver types.  I don't think we should
> change Mercury's execution model.

I don't think it's the execution model, it's the assumption that
anything not free is ground.  Anyway, disallowing \= for any inst
variables seems wrong, because disequality constraints are perfectly
sensible.  Forbidding the most obvious expression of disequalities is
unneighborly when there's a reasonable way to allow them (ie, allowing
the solver writer to specify the method).

Peter Schachte              In order to become the master, the politician
schachte at cs.mu.OZ.AU        poses as the servant.
www.cs.mu.oz.au/~schachte/      -- Charles de Gaulle 
Phone: +61 3 8344 1338      
mercury-users mailing list
post:  mercury-users at cs.mu.oz.au
administrative address: owner-mercury-users at cs.mu.oz.au
unsubscribe: Address: mercury-users-request at cs.mu.oz.au Message: unsubscribe
subscribe:   Address: mercury-users-request at cs.mu.oz.au Message: subscribe

More information about the users mailing list