🚀 go-pugleaf

In article <DOWDING.90Nov13152422@palm.ai.sri.com>, dowding@ai.sri.com (John Dowding) writes:
> In article <264@messina.cs.utexas.edu> bradley@cs.utexas.edu (Bradley L. Richards) writes:
>*  As near as I can tell, setof and bagof don't work properly with the
>*  "recorded" predicate in Quintus Prolog (version 2.5.1, sun3-4.0). ...
>*   and then query:  setof(X, recorded(woof, X, _), Set).
> It is trickey.  This would work:
> 	setof(X, Ref^recorded(woof, X, Ref), Set)

> Prolog doesn't have a true don't-care variable.  The _ is really
> just a shorthand for some particular variable that you haven't
> bothered to name.  

Just to stress this:  this behaviour has *nothing* to do with recorded/3
at all.  setof/3 is in this instance behaving *exactly* the way it is
*supposed* to work, and any Prolog giving different results _would_ have
a bug.  (See the last chapter in The Craft of Prolog, plug plug.)
You may prefer to use findall/3.

-- 
The problem about real life is that moving one's knight to QB3
may always be replied to with a lob across the net.  --Alasdair Macintyre.