Id dint know the atomspace did this, and I would be annoyed to find it showing up in results unexpectedly. I agree, determining semantic equivalence is the job of a Mind Agent.
There's my semi-annual 2 cents. All the Best, Matt -- Standard Disclaimer: Please interpret brevity as me valuing your time, and not as any negative intention. On Fri, Oct 21, 2016 at 8:55 AM, 'Nil Geisweiller' via opencog < opencog@googlegroups.com> wrote: > Hi, > > I start to think that automatic alpha-conversion is evil. > > First let me recall what it does. Say you've added > > (Scope (VariableList (Variable "$X") (Variable "$Y")) > (And (Variable "$X") (Variable "$Y"))) > > and you subsequently add > > (Scope (And (Variable "$gold") (Variable "$silver"))) > > then recalling the handle of that last addition, you'd get the first > alpha-equivalent scope, which is > > (Scope (VariableList (Variable "$X") (Variable "$Y")) > (And (Variable "$X") (Variable "$Y"))) > > This is rather confusing to the user, but even worse the pattern matcher > behaves differently with the former or the latter. If you use the former to > match grounds containing variables "$X" and "$Y" it may not work due to the > pattern matcher discarding self-matches. The latter would match UNLESS the > former has been previously added, because the variables "$gold" and > "$silver" would be silently replaced by "$X" and "$Y". This is horribly > confusing to the user! > > Second, it seems rather arbitrary to try to detect this kind of > equivalence while there's an infinity of others. For instance > > (And (Variable "$X") (And (Variable "$Y")) > > is equivalent to > > (And (Variable "$X") (Variable "$Y")) > > For these reasons I think semantic equivalence detection shouldn't be > incorporated into the AtomSpace. The AtomSpace should take care of the > syntax only (OK, with the exception of unordered links), as it's always > been, and this task should differed to another process working above the > AtomSpace. > > It was suggested a while ago to have a normal form reduction engine for > the AtomSpace, similar to MOSES', and such an engine could be used to > reduce while adding atoms, if the user chooses so. This is a much cleaner > way to handle that. Also since semantic equivalence is undecidable, there > will always be a battle between completeness and performance. Another > reason to have this ever growing monster above the AtomSpace rather than in > it. > > OK, I don't know if I've convinced you, or even if I've convinced myself, > but it's really a discussion we need to have. > > Opinions welcome. > > Nil > > -- > You received this message because you are subscribed to the Google Groups > "opencog" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to opencog+unsubscr...@googlegroups.com. > To post to this group, send email to opencog@googlegroups.com. > Visit this group at https://groups.google.com/group/opencog. > To view this discussion on the web visit https://groups.google.com/d/ms > gid/opencog/580A3A75.1020708%40gmail.com. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "opencog" group. To unsubscribe from this group and stop receiving emails from it, send an email to opencog+unsubscr...@googlegroups.com. To post to this group, send email to opencog@googlegroups.com. Visit this group at https://groups.google.com/group/opencog. To view this discussion on the web visit https://groups.google.com/d/msgid/opencog/CAPE4pjCxAS4sV%3DuXkqJucbdSbgC_KGqEiyu7K9jQVDuiPhwG%3Dg%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
