My answer was too brief. Link-grammar is a kind of CCG, where the morphisms are are given streamlined, less klunky labels, called "types". A branch of mathematics called "type theory" explains how types and categories are dual to each other, and how talking about types often provides a simpler, deeper insight than talking about categories. But they are the "same thing" in a certain sense.
More precisely, categories have an "internal hom" functor, and that hom defines the "internal language" of the category. The most famous example is that the "internal language" of closed cartesian categories is simply-typed lambda calculus. This can be seen as a form of Curry-Howard correspondence. John Baez and Bob Coecke have written extensively on this topic; before them was Lambeck and many others. Roughly speaking, types describe how morphisms can be composed; they describe allowed combinations. I think I wrote previously about how I believe that we can beat other research: by using what are called "sections of a sheaf" in mathematics, and are called "disjuncts" in link grammar. Here's why: Pretty much all work on meaning uses vector spaces (e.g. word2vec, and so on) and vector spaces are a certain kind of category with a certain kind of internal language, that we know, a priori, is not quite right for the categories that describe language. To overcome this limitation, I believe that by using sections of a sheaf (i.e. link-grammar disjuncts) we can locally "glue together" the necessary semantic space, in the correct shape, instead of assuming that it is flat, which is what vector spaces do. Of course, I am just throwing around big words here. The actual work is harder, and I just spent the last month creating a dataset which turns out to have a deep, maybe fatal flaw. Its a lot of work to take a small step. --linas On Sun, Jul 9, 2017 at 1:23 PM, Linas Vepstas <[email protected]> wrote: > Link Grammar is a certain kind of CCG. -- linas > > On Sun, Jul 9, 2017 at 6:15 AM, Alex <[email protected]> wrote: > >> Probably offtopic - while I am reading about OpenCog community efforts in >> NLP, I am quite suspicious about statistical methods. I think that the only >> meaningful approach to the NLP ir the combinatory categorial grammars >> (Lambek calculus, Montague semantics) and this effort tries to translate >> natural language sentences into logical expressions - lambda calculus >> expressions. So - if there is connection between Schema as a language of >> lambda calculus, then CCGs are the way of translating NL sentences directly >> into Scheme structures. Besides CCGs approach uses white box approach and >> understanding for the semantics of natural language, these semantical >> knowledge can also be encoded as the Scheme/OpenCog structures and can be >> learned of enhanced by time. >> >> Of course, raw statistical approach in the end can give the same results, >> but structured approach can be more feasible. Besides - statistical >> approach yields results that are worth all or nothing. But CCG approach >> yields results that are improving step by step and such improving >> understanding reflects the human approach to the world and language - >> humans progresively learns language, its syntax and semantics. I we have >> the slightest doubts about existence of the perfect understanding of the >> language then we should also must have doubts about efficiency of the >> statistical approach. >> >> -- >> 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/ms >> gid/opencog/393b88c8-aadd-456c-bd84-eaac92b55fd8%40googlegroups.com >> <https://groups.google.com/d/msgid/opencog/393b88c8-aadd-456c-bd84-eaac92b55fd8%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> 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/CAHrUA355vJre7Vo%2BzejVCmtbHbKtjnqne04BMh5DqoBsNxexmw%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
