Return-Path: Message-Id: Date: Mon, 13 May 91 02:13 EDT From: lojbab (Bob LeChevalier) To: lojban-list Subject: anaphora, especially donkey sentences and the like: Status: RO X-From-Space-Date: Mon May 13 02:14:01 1991 X-From-Space-Address: lojbab In response to David Elsworthy: Nora looked David Elsworthy's postings over and helped me out with the logical questions in his anaphora posting. She did not see any of them as particularly problematical in Lojban; the problems of the English disappear in reformulating the sentences for Lojban grammar. Here are my attempts at each of David's examples. Hopefully they will show something useful. Basically I'm using long-form lujvo so that everyone can easily determine the source gismu. I'm also not explicitly using prenex constructions. I have given existentially quantified anaphora solutions to the problems in most cases, and showed shorter "le" and "lo" forms for some of these - the other ones could be similarly shortened. >(1) Every farmer who owns a donkey beats it. ro da poi cangyprenu zi'e poi ponse de poi xasli cu raplydarxi de ro da poi cangyprenu zi'e poi ponse de poi xasli each something-x which farm-persons and which possesses something-y which asses cu raplydarxi de repeat-hits that-y Or more briefly by implicit reference to the "da" of the last version: ro cangyprenu poi ponse de poi xasli cu raplydarxi de ro cangyprenu poi ponse de poi xasli each farm-person which possesses something-y which asses cu raplydarxi de repeat-hits that-y Or even more briefly using a description and no explicit existentials: ro cangyprenu poi ponse lo xasli cu raplydarxi ri ro cangyprenu poi ponse lo xasli each farm-person which possesses something/things that are asses cu raplydarxi ri repeat-hits the-last-it/them. In the last, "ri" could be replaced by "le xasli" ("the ass(es)", which pragmatically refers back to the donkey(s) that is/are owned. This might be necessary/useful for more complex constructs where "ri" cannot be conveniently used. "le" constructions as anaphora are less logically precise than explicit anaphora, but in situations even much more complex than this, it shouldn't be too hard to resolve the references. You also could assign "ko'a" to the owned donkeys (e.g. "lo xasli goi ko'a", and use "ko'a" in the anaphora if the anaphoric reference was not immediately following as it conveniently is in this sentence. >The simple word copying approach gets us: > >(2) Every farmer who owns a donkey beats a donkey. In Lojban, this is clearly different. In the long existential expansion, it is: ro da poi cangyprenu zi'e poi ponse de poi xasli cu raplydarxi di poi xasli ro da poi cangyprenu zi'e poi ponse de poi xasli each something-x which farm-persons and which possesses something-y which asses cu raplydarxi di poi xasli repeat-hits something-z which asses And I can shorten this using a tricky-by-English-standards usage to: ro cangyprenu poi ponse loi xasli cu raplydarxi loi xasli ro cangyprenu poi ponse loi xasli each farm-person which possesses of the mass of Ass-dom cu raplydarxi loi xasli repeat-hits of the mass of Ass-dom. or colloquially back to English. Every farmer that owns Ass beats Ass. (where Ass is the mass individual) [Side explanation - since most people don't understand the Lojban masses: When "you" are holding a pencil, it is usually true that only part of one hand actually does the holding. Your hand is "you" for the purpose of holding. In the above sentence any ass meeting the x2 position in relation "ponse" to a farmer in x1 represents the entirety of Assdom. Similarly, any ass (not necessarily the same as the above) which fits the x2 position in relation "raplydarxi" to x1 - a farmer who owns an ass, also represents all of Ass-dom. Many English mass nouns work somewhat like this, though not completely: "Every person is made mostly of water and drinks water." Clearly the two "water"s are not the >same< water. But in "Every person who likes water drinks water", the two masses of water overlap. Yet the person who "likes water" probably is not too fond of hydrochloric acid, which is mostly water. End of digression. Mass is a fun concept, but a different area of logic than David asked about.] >(3) Every farmer who owns a donkey beat a donkey which he owns. ro da poi cangyprenu zi'e poi ponse de poi xasli cu raplydarxi di poi xasli zi'e poi se ponse da ro da poi cangyprenu zi'e poi ponse de poi xasli each something-x which farm-persons and which possesses something-y which asses cu raplydarxi di poi xasli zi'e poi se ponse da repeat-hits something-z which asses and which is-possessed-by x This is just a restrictive clause on the latter form, and clearly be seen to not necessarily say that "de" is being beaten. >which is better, but still leaves a problem. It isn't clear whether (1) >commits each farmer to beating all the donkeys he owns, but in an >example like > >(4) Every man who loves a woman likes her. > >(assuming "love" implies "like"), there does seem to be such a >commitment. ro da poi nanmu zi'e poi prami de poi ninmu cu nelci de ro da poi nanmu zi'e poi prami de poi ninmu each something-x which mans and which loves something-y which womans cu nelci de likes her. > The paraphrase: > >(5) Every man who loves a woman likes a woman who he loves. > >does not seem to have the same reading. ro da poi nanmu zi'e poi prami de poi ninmu cu nelci di poi ninmu zi'e poi da prami ro da poi nanmu zi'e poi prami de poi ninmu each something-x which mans and which loves something-y which womans cu nelci di poi ninmu zi'e poi da prami likes something-z which womans and which he loves. >The copying problem can also be seen in another classic sentence, known >as the Bach-Peters paradox: > >(6) The boy who deserves it will get the prize he wants. > >On the simple copying approach, we have "it" = "the prize he wants", and >"he" = "The boy who deserves it". It is fairly clear that this leads to >an infinite regress if you try to expand it out. Thinking Lojbanically offers a different insight as to what "it" means that makes this simple even in English. But first let me do it David's way, in case I'm full of hot air. The regression is lost in converting this to Lojban. First a literal translation that keeps the late definition of the anaphora but makes the "copying" clear: le nanla goi ko'a poi jerna ko'e cu cpacu ko'e goi lo velcnemu poi ko'a djica le nanla goi ko'a poi jerna ko'e cu cpacu The boy also-known-as x1 which earns x2 gets ko'e goi lo velcnemu poi ko'a djica x2 which-is-defined-as the-thing-that is-a-reward which x1 desires This could also be done with a prenex-quantified variable instead of "ko'e" which removes any qualms about using the "ko'e" without defining it first; actually, I guess, you could put the "ko'e" in the prenex, too. Nora prefers writing this sentence with existentials and a double-level relative clause: da poi nanla zi'e poi jerna de poi velcnemu zi'e Something-x which boys and which earns something-y which is-a-reward and poi da djica de cu cpacu de which x wants y gets y or without existentials and using a subscripted relative pronoun: le nanla poi [ke'a] jerna le velcnemu poi ke'axire djica ke'a cu cpacu ri le nanla poi [ke'a] jerna le velcnemu poi ke'axire djica ke'a cu cpacu ri The boy which he earns the-reward which he wants it gets it Lojban allows infinitely nested relative clauses. On later thinking, though, I think the English and Lojban versions of David's problem resolve easily using a different interpretation of the above. This interpretation is natural for Lojban as a language with explicit "abstract nouns". In this version, "it" = "getting the prize that he wants", expanding to: "The boy who deserves getting the prize he wants will get the prize he wants." which works fine in English to eliminate the infinite regression. (I can't say that this will work for all such paradoxes, but I'm reasonably proud of this one - at least till you people all tear me up on it.) Existential: da poi nanla zi'e poi jerna lenu da cpacu de poi velcnemu zi'e poi da djica de cu cpacu de da poi nanla zi'e poi jerna lenu da cpacu Something-x which boys and which earns the-event-of x gets de poi velcnemu zi'e poi da djica de cu cpacu de something-y which is-a-reward and such-that x wants y gets y Non-Existential: le nanla goi ko'a poi jerna lenu ko'a cpacu [ko'e goi] le velcnemu poi ko'a djica ke'a cu cpacu [ko'e | le velcnemu poi ko'a djica] le nanla goi ko'a poi jerna lenu ko'a cpacu The boy also-known-as x1 which earns the-event-of x1(he) gets [ko'e goi] le velcnemu poi ko'a djica ke'a cu cpacu [x2 which-is-defined-as] the reward which x1(he) wants it gets [ko'e | le velcnemu poi ko'a djica] [x2(it) | the reward which x1(he) wants] >The conclusion from this is that the interpretation of anaphors is *not* >the business of the parser, or of the syntactic component in any sense. >Indeed, in English, there are very few syntactic constraints on >anaphora: number, gender, and a restriction on reflexivity in sentences >like: >(7) John talks to him. (wrong if him=John) The paradoxes in these are dependent on English's ambiguous sex-linked pronouns. Lojban does both pronouns and reflexives differently than English. la djan. tavla da poi nakni la djan. tavla da poi nakni John talks-to something-x which males la djan. tavla vo'a la djan. tavla vo'a John talks-to the-x1-of-this-bridi (himself). >(8) John talks to himself. Jane talks to *himself. (him if we want Jane >talking to John). IN Lojban, the parallel construction doesn't mean the same thing: la djan. tavla vo'a .i la djein. tavla vo'a la djan. tavla vo'a John talks-to the-x1-of-this-bridi (himself) .i la djein. tavla vo'a and... Jane talks-to the-x1-of-this-bridi (herself). On the other hand, I can give a good example of "ra'o" here, which shows how repetitions of anaphoric references can be expressed: la djan. tavla vo'a .i la djein. go'i la djan. tavla vo'a John talks-to the-x1-of-this-bridi (himself) .i la djein. go'i and... Jane (has the last relationship = talks-to the-x1-of-THAT-bridi (himself = John). means that the referent of "vo'a" is unchanged in the go'i sentence, so that Jane talks to John, while: la djan. tavla vo'a .i la djein. go'i ra'o la djan. tavla vo'a John talks-to the-x1-of-this-bridi (himself) .i la djein. go'i ra'o and... Jane (has the last relationship with "vo'a" re-evaluated = talks-to the-x1-of-THIS-bridi (herself = Jane). means that "vo'a" is re-evaluated in the new sentence environment, and thus refers to Jane. The default of non-update is because the most frequent use of "go'i" is as a yes answer to a yes/no question, which would not work with automatic update: John: "Did you talk to me?" Jane: "Yes (I talked to you)" - not "Yes (you talked to me)". > Every farmer who owns a donkey beats it. ?It neighs. > >which is found to be unacceptable by most people, except when you >imagine that the second sentence is somehow still within the scope of >the "every". (The unacceptability isn't too clear here, I know: please >take it for granted that the general evidence is that you can't have a >singular anaphor in later sentences.) > >A problem possibly arises with this: > Every farmer who owns a donkey beats it. They neigh. Since Lojban does not distinguish between singular and plural, this distinction doesn't occur in an unmarked sentence. In a quantified sentence, you would of course extend the scope anyway: ro da poi cangyprenu zi'e poi ponse de poi xasli cu raplydarxi de .ije de xirmybacru ro da poi cangyprenu zi'e poi ponse de poi xasli each something-x which farm-persons and which possesses something-y which asses cu raplydarxi de .ije de repeat-hits that-y logical-AND-sentence-(continuing scope) that-y xirmybacru horse-utters It is indeed tricky to find a way to show some >other< meaning for the plural "they" (unless "they" are the farmers, in which case ".ije roda xirmybacru"). Incidentally, while Lojban's design is based >primarily< on 1st order predicate logic, there are elements of higher order logics built in as well (e.g. notably, I'm told, in quantified predicate variables, but questions on this REALLY must go to pc). I'm even hoping that we have at least a partial basis for fuzzy logic built in, though no one has really looked at Lojban closely from that perspective. -lojbab