On Thu, Jan 16, 2020 at 3:28 PM Alexander Gabriel <[email protected]> wrote:
> >> PresentLinks and AlwaysLinks are "reserved keywords" intended for the >> pattern matcher, only. If you defocus your eyes a bit, then sure, they >> seem to resemble the predicate-logic "there-exists" and "for-all" . But >> the were not designed for reasoning, there were designed for solving the >> "subgraph isomorphism problem" and for "term rewriting". So if you actually >> need the predicate-logic constructs "there-exists" and "for-all", then you >> should use the ThereExistsLink and ForAllLink. (These have been so >> under-utilized in the code base that they might have been stripped out; but >> they could be added back in. ). >> >> Hi Linas, > those are binding though, right? So, how do I combine them with their own > kind as well as other links in a consistently binding way? > Since the ExistsLink and ForAllLink are more-or-less unused, and as such, they do not really have any well-defined semantics. I guess the PLN book talks about them ... but the book and the code-base are divergent in various ways. I suspect that there are no PLN rules written for them (I don't know). If I look at the code, I see this: atom_types.script:FORALL_LINK <- SCOPE_LINK,CRISP_OUTPUT_LINK "ForAllLink" atom_types.script:EXISTS_LINK <- SCOPE_LINK,CRISP_OUTPUT_LINK I'm pretty sure I wrote that because it seemed to "make sense" at the time. So, yes a ScopeLink is "binding" (if we're talking about the same thing). This is a good time to narrow-down and give a precise semantics for these two link-types. And/or use or abuse them, since they are currently lying fallow, unclaimed, unused. -- Linas -- cassette tapes - analog TV - film cameras - you -- 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 [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/opencog/CAHrUA36yW87i8aysd4%2BXmE832rkLEb6BdOBaq3x0EQH0tAhcJw%40mail.gmail.com.
