[m-dev.] Re: [mercury-users] Mutual Exclusivity & Exhaustiveness

[Peter Schachte]

> > 	:- all [X, Y] promise_exactly_one_solution (
> > 		X < Y
> > 		; X = Y
> > 		; X > Y
> > 	).

There's something else I find confusing about this.  Of course forall X, Y

	(X < Y ; X = Y ; X > Y)

can have at most one solution, because it has no outputs.  I only see this
declaration promising exhaustiveness, not exclusivity.  I don't see it
promising that for all X and Y, the success of any one of these atoms
entails the negation of all the others.

-- 
Peter Schachte              I have not yet begun to procrastinate. 
schachte at cs.mu.OZ.AU        
www.cs.mu.oz.au/~schachte/  
Phone: +61 3 8344 9166      
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