I guess the argument for having a link type "BeliefLink" is that Sumit created specific quantitative truth value formulas to deal with BeliefLink .... Of course these formulas could also be used together with "PredicateNode 'belief' " as well, but so far typically when we have specific math formulas for manipulating the parameters of a certain predicate, we've made it a link type...
ben On Wed, Mar 15, 2017 at 11:45 AM, Linas Vepstas <[email protected]> wrote: > I updated the wiki page to mention it, and also mention that a BeliefLink > is the same as EvaluationLink Predicate "belief". Not only would a port > into the current PLN infratructure be useful, but that should be followed by > a tutorial/example, and there should also be a hookup into the chatbot. That > would ... make for a fun demo. > > > On Wed, Mar 15, 2017 at 11:40 AM, Ben Goertzel <[email protected]> wrote: >> >> Hmm, OK, it's been a while since that work was done and almost as long >> since I looked at it >> >> The crux of Sumit's work was to modify the PLN truth value formulas to >> work sensibly for these modal-logic operators (belief, etc.). That >> part was solid and I remember it. But the choice of link types he >> used, I don't remember well and would need to revisit... probably >> you're right that it needs revisiting... >> >> >> >> On Wed, Mar 15, 2017 at 11:36 AM, Linas Vepstas <[email protected]> >> wrote: >> > I just skimmed that code, and it does not seem to make use of the KR >> > structures described in http://wiki.opencog.org/w/Claims_and_context >> > and >> > instead invents new link types .. e.g. BeliefLink. This leads to a >> > proliferation: you'd need BeliefLink, SayLink, >> > TellLink,UseToBeleiveInThePastLink, LieLink etc. So its not just a >> > port, >> > but a fairly serious restructuring. >> > >> > --linas >> > >> > On Wed, Mar 15, 2017 at 11:14 AM, Ben Goertzel <[email protected]> wrote: >> >> >> >> Code and theory for extending PLN to handle modal reasoning regarding >> >> beliefs, knowledge and so forth is here: >> >> >> >> >> >> >> >> https://github.com/sumitsourabh/opencog/tree/patch-1/opencog/reasoning/pln/rules/epistemic-reasoning >> >> >> >> This was carefully worked out by Sumit Sourabh and Matt Ikle' a few >> >> years >> >> ago. >> >> >> >> The code needs to be merged into the current version of PLN. This >> >> would be a useful thing for someone to do, and then write associated >> >> unit tests. >> >> >> >> -- Ben >> >> >> >> >> >> On Wed, Mar 15, 2017 at 11:07 AM, Linas Vepstas >> >> <[email protected]> >> >> wrote: >> >> > >> >> > >> >> > On Sat, Mar 11, 2017 at 10:25 PM, Alex <[email protected]> >> >> > wrote: >> >> >> >> >> >> Hi! >> >> >> >> >> >> There can be modalities (which are usually expressed as diamonds or >> >> >> boxes >> >> >> (operators) in modal logic): >> >> >> DUTY_TO_PERFORM_ACTION(agent, action, time horizone) - agent should >> >> >> perform action within time horizon >> >> >> BELIEF(agent, statement, time instant) - agent believes in statement >> >> >> at >> >> >> the time instant >> >> > >> >> > >> >> > >> >> > Wasn't this discussed in some other thread, just recently? >> >> > EvaluationLinks are the standard way of representing knowledge in >> >> > opencog. >> >> > See wiki for that. >> >> > >> >> > Also see wiki about how to represent beleifs .. there is some section >> >> > there >> >> > that discuses this, I don't recall where, or what it said. >> >> > >> >> > We've had prior discussions on the mailing list about representing >> >> > beleifs; >> >> > but we only had a minimal discussion about reasoning over them. This >> >> > is >> >> > one >> >> > area that should be clearified, and if new PLN rules are needed to >> >> > handle >> >> > this, then now is a good time to figure that out. >> >> > >> >> > --linas >> >> > >> >> >> >> >> >> >> >> >> Such modalities are important in robotics (e.g. AGI safety - what >> >> >> duties >> >> >> and permissions robots have) and in communication (modelling other >> >> >> agent >> >> >> believes, knowledge and reasoning styles). >> >> >> >> >> >> Important point is, that by introducing modalities we also introduce >> >> >> additional axioms/meta-rules that connect modal statements >> >> >> (statements >> >> >> under >> >> >> modal operator) with the nonmodal statements and with the statements >> >> >> of >> >> >> other modalities (modal conversion). Example list of such metarules >> >> >> are >> >> >> available in https://en.wikipedia.org/wiki/Modal_logic. Such >> >> >> metarules >> >> >> sometimes are debatable, e.g. rule in deontic logic: >> >> >> DUTY_TO_PERORM_ACTION(agent, >> >> >> action)->PERMISSION_TO_PERFORM_ACTION(agent, >> >> >> action) and such metarules sometimes lead to paradoxes (classical >> >> >> deontic >> >> >> logic is full of them), nevertheless, such metarules expresses >> >> >> additional >> >> >> knowledge about reality. And such metarules can be mined and used >> >> >> for >> >> >> constraining inference process (inference control)! >> >> >> >> >> >> I have two questions regarding expression of modalities in OpenCog?: >> >> >> 1) how we can express modalities in Scheme/atomspace? >> >> >> -- One solution is to introduce new link types. Is such introduction >> >> >> possible? Maybe OpenCog have GenericLink for which the user form >> >> >> derivation >> >> >> and for the derivation the user can define syntax (how many Nodes >> >> >> and >> >> >> of >> >> >> what Type are allowed in the new Link) and semantics (what processes >> >> >> are >> >> >> done, what is output and strenght values of the output)? I have not >> >> >> heard >> >> >> about such option; >> >> >> -- Another solution is to use PredicateNode, e.g. belief can be >> >> >> expressed: >> >> >> PredicateNode "agent_believe" >> >> >> ConceptNode "Erving" >> >> >> ConceptNode "Door is open" >> >> >> The question is - can be use other Node, Link, result of >> >> >> SatisfyingSetLink >> >> >> etc. in place of the literal "agent_believes"? Or we are bounded for >> >> >> using >> >> >> literal constants in the PredicateNode? If former is true, then the >> >> >> system >> >> >> is open for the arbitrary set of modalities and the system can >> >> >> generate >> >> >> new >> >> >> modalities! >> >> >> >> >> >> 2) how we can express metarules for modalities in OpenCog?: >> >> >> My proposal is to use rules that accepts some patterns of predicates >> >> >> and >> >> >> that generates new predicates: >> >> >> >> >> >> >> >> >> >> >> >> rule_body(obligation_predicate_type_nodes)->rule_head(new_permission_predicate_type_nodes) >> >> >> Again - the question is about flexibility of the system: is the >> >> >> system >> >> >> allows generation of new link types or new predicate then the system >> >> >> can >> >> >> mine/generate the relevant rules for the newly generate modalities! >> >> >> >> >> >> Of course, I am studying literature, experimenting, thinking about >> >> >> this, >> >> >> but maybe someone also has thought about those questions and has >> >> >> already >> >> >> something done - it would be nice to hear thoughts, proposals and >> >> >> experience! >> >> >> >> >> >> Thanks! >> >> >> >> >> >> -- >> >> >> 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 post to this group, send email to [email protected]. >> >> >> 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/f70e8da1-1147-41e9-8aa6-c2acbab14ce6%40googlegroups.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 [email protected]. >> >> > To post to this group, send email to [email protected]. >> >> > 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/CAHrUA36r01Q%3DKbXsJE3%2BS2KbpfQ3oZ5WD%2B-XY_dfPP6PCPhdEw%40mail.gmail.com. >> >> > >> >> > For more options, visit https://groups.google.com/d/optout. >> >> >> >> >> >> >> >> -- >> >> Ben Goertzel, PhD >> >> http://goertzel.org >> >> >> >> “Our first mothers and fathers … were endowed with intelligence; they >> >> saw and instantly they could see far … they succeeded in knowing all >> >> that there is in the world. When they looked, instantly they saw all >> >> around them, and they contemplated in turn the arch of heaven and the >> >> round face of the earth. … Great was their wisdom …. They were able to >> >> know all.... >> >> >> >> But the Creator and the Maker did not hear this with pleasure. … ‘Are >> >> they not by nature simple creatures of our making? Must they also be >> >> gods? … What if they do not reproduce and multiply?’ >> >> >> >> Then the Heart of Heaven blew mist into their eyes, which clouded >> >> their sight as when a mirror is breathed upon. Their eyes were covered >> >> and they could see only what was close, only that was clear to them.” >> >> >> >> — Popol Vuh (holy book of the ancient Mayas) >> >> >> >> -- >> >> 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 post to this group, send email to [email protected]. >> >> 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/CACYTDBdLatMo%2BSErmaU6g2An1YfiqmNcPBN_ru-MNcFwxxY6Eg%40mail.gmail.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 [email protected]. >> > To post to this group, send email to [email protected]. >> > 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/CAHrUA34BEp9WsoTMMw44nT-%3DCv%2BQE1i9%3D2bRg-NvSmEsekzy1g%40mail.gmail.com. >> > >> > For more options, visit https://groups.google.com/d/optout. >> >> >> >> -- >> Ben Goertzel, PhD >> http://goertzel.org >> >> “Our first mothers and fathers … were endowed with intelligence; they >> saw and instantly they could see far … they succeeded in knowing all >> that there is in the world. When they looked, instantly they saw all >> around them, and they contemplated in turn the arch of heaven and the >> round face of the earth. … Great was their wisdom …. They were able to >> know all.... >> >> But the Creator and the Maker did not hear this with pleasure. … ‘Are >> they not by nature simple creatures of our making? Must they also be >> gods? … What if they do not reproduce and multiply?’ >> >> Then the Heart of Heaven blew mist into their eyes, which clouded >> their sight as when a mirror is breathed upon. Their eyes were covered >> and they could see only what was close, only that was clear to them.” >> >> — Popol Vuh (holy book of the ancient Mayas) >> >> -- >> 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 post to this group, send email to [email protected]. >> 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/CACYTDBevfrcxtXTr3XkPHL5P9OaG2Jnrc5-oKyJXJ8CBTn0i%2Bg%40mail.gmail.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 [email protected]. > To post to this group, send email to [email protected]. > 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/CAHrUA35e5m6yo6iSXsYLEBaLB5NJOEb6b02%2B57XxLJbkZ3BweQ%40mail.gmail.com. > > For more options, visit https://groups.google.com/d/optout. -- Ben Goertzel, PhD http://goertzel.org “Our first mothers and fathers … were endowed with intelligence; they saw and instantly they could see far … they succeeded in knowing all that there is in the world. When they looked, instantly they saw all around them, and they contemplated in turn the arch of heaven and the round face of the earth. … Great was their wisdom …. They were able to know all.... But the Creator and the Maker did not hear this with pleasure. … ‘Are they not by nature simple creatures of our making? Must they also be gods? … What if they do not reproduce and multiply?’ Then the Heart of Heaven blew mist into their eyes, which clouded their sight as when a mirror is breathed upon. Their eyes were covered and they could see only what was close, only that was clear to them.” — Popol Vuh (holy book of the ancient Mayas) -- 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 post to this group, send email to [email protected]. 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/CACYTDBe%2BSTFXVWWBCH8qTZt7ZZrmiKH25LcqAC%3D5hrS2heQNEg%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
