10
I don't personally believe that CFL are insufficient, but among linguists who care about weak generative capacity (probably most don't care about the issue), the consensus seems to be that they are. The usual reference given is an article by Peter Shieber, which is online here, and which is, in my opinion, an admirable work of scholarship. (Which doesn't ...
6
The treatment of English worked out in Generalized Phrase Structure Grammar by Gazdar, Klein, Pullum, & Sag is a CFG (with sets of rules given in highly abbreviated form) and is comprehensive in the sense that it includes the main areas of English covered in the TG literature. It is not a practical description, because there are too many rules, but it ...
4
The most famous example of a phenomenon which seems to argue against the context-freeness of natural language is cross-serial dependencies in Swiss German (Schieber, '85) (cross-serial dependencies can also be found in Dutch).
Two facts about Swiss German are relevant here:
Objects are case-marked (dative and accusative), diff. verbs sub-categorise for ...
4
It's hard to nail down a scientific difference between functionalist and formalist approaches, because the goals and domains of investigation are usually disjoint. If you want some opposite ends of the spectrum, you could compare David Stampe's dissertation on Natural Phonology with this paper. The main question is whether there is an autonomous ...
4
No, natural language is not a formal system. Some rather interesting theories about natural langages are formal systems. But to confuse a theory with the phenomena that it is a theory of is incoherent, in my opinion. Did Newton propose that our solar system was a differential calculus? Of course not. He invented the latter to describe the former.
Is it ...
4
The author has mistaken language and grammar, and that criticism isn't valid for any period of generative phonology. Grammar is a cognitive ability which can be modeled as a particular kind of formal system. Language is a kind of behavior that is the product of a number of cognitive and physical systems, one of which is grammar. The viewpoint expressed by ...
3
There's no terminology that generically describes all such differences, but the most likely kind of difference, what I suppose you have in mind, relates to the idea of a "verb form" – under that heading you would include for instance "saw", "seeing", "seen". In English, verbs can have a number of forms depending on ...
3
Some remarks are necessary before answering such a question. CFGs have been an important step in the history of formal grammars, but it is not exactly the example we want to follow in DG and in natural language modelling in general. CFGs are string rewriting systems, that is, grammars that generate sets of strings of words. But to speak English is not to be ...
3
The formalizations of dependency theory exist. In fact I have a colleague who specializes in mathematical formalizations of principles of syntax, and he is more a DG guy (dependency grammar) than a PSG guy (phrase structure grammar). But he and I disagree about the value of the formalizations that he employs. I do not understand his formalizations and see ...
3
The context free rewrite rules - as associated most with early Chomskyan syntax - can easily be reworked in terms of dependency: G = (T, R), where T is the set of terminals and R is the set of rewrite rules. The distinction between nonterminal symbols (V) and terminal symbols (T) disappears, only terminals remaining. If one needs a start symbol, it would ...
2
Despite not being so hot when it comes to formal language theory, i decided to take a stab at an answer after all (using this as a reference). Here is the grammar for the language L = {ww ∣ w ∈ {a,b,c} ∗ }, which consists of a set of rewrite rules:
S[x] -> S[xf] | S[xg] | S[xh]
S[x] -> T[x]T[x]
T[xf] -> T[x]a
T[xg] -> T[x]b
T[xh] -> T[x]c
T[] -> ...
2
There are formalized dependency-based grammars, such as Meaning-Text Theory or Functional Generative Description. A simple Google search will give you links to papers and books.
2
Your question is confused. You confuse a grammar (an entity) with its expression (a language). So by very definition, the grammar of any language (formal or informal) is expressed in a metalanguage.
However, the difference between "formal" and natural languages is that a grammar of a natural language is always expressed in a metalanguage which is a part of ...
2
Simplified Tree Diagram of Supplementary Adjunct:
2
In a manner of speaking, yes. The analysis of phrases into immediate constituents is not really a matter of theory, but more a matter of fact, which any grammatical theory must provide for. So, in this sense, every grammar formalism must tell you about constituency (even dependency grammar).
If, however, by constituency grammar you mean a grammatical ...
2
If you generate (or parse, same thing in reverse) both of the strings at the same time, one token at a time, your grammar can only be in a limited number of states (strings are (still) the same, strings differ so the rest doesn't matter, etc.). Even though we as humans like to parse the string from left to right, the way we read it, a context-free grammar ...
2
The NLTK book, chapter 10, which provides some theoretical background to the implementation, references NLTK ch. 9, where the feature grammar is introduced. Have you read these articles?
Ch. 9 explains all the the features you were asking about including the ? notation.
Ch. 10 introduces the lambda calculus. The special function app in the ...
2
It is a relative clause. A plot of land is acting as the lexical head of the RC, and in relation to was 'moved' to before the relative pronoun (not conjunction) which through the process of pied piping; you can see more examples on the Wikipedia page linked.
2
No natural language is deterministic. What book mentions LR parsers for English?
There might be some “controlled languages” based on English that are deterministic, but a broad-coverage parser is always non-deterministic, there are typically many syntactic ambiguities that get resolved later at the level of semantics or pragmatics.
In actual fact, many ...
2
Are you aware of CCGbank (Hockenmaier, 2003)? This is the largest-scale corpus of English text annotated with CCG categories, consisting of ~1 million tokens of text, and is derived semi-automatically from the Penn Treebank.
This was used by Clark & Curran (2007) in a line of work to train wide-coverage dependency parsers for English, which made use of ...
2
By "generativism", I assume you mean "the theory of Generative Grammar". This is a theory promulgated by Chomsky starting, in one form, in 1951. It came to be known as "generative grammar" with the publication of Aspects of the theory of syntax (see chapter 1). The word "generate" is taken from mathematics, with ...
1
For general use as an argument: You need EITHER a silent determiner (or another head) that converts <e,t> to either <<e,t>,t> or e OR a theory of coercion that performs its function for you. Needless to say, I prefer the former.
However, "in other words, an expression of type <e, t> cannot combine with another expression of type &...
1
Agnes has already explained the intuition why the language is context-free. Here are three more concrete tips that may be helpful:
1
One example is generating relative clauses parses with an intuitive structure. In a CFG, we'd need to define new rules to deal with the syntax of the relative clause in the following sentence, since "saw", a transitive verb, isn't taking an object in the expected position (this would give us a grammar that has the same weak generative capacity as what we ...
1
Substitution versus Replacement
Hans Reichenbach in his classic Elements of Symbolic Logic distinguishes between substitution for a variable and replacement of an expression. Substitution is uniform, in the sense that the same value must be substituted for each instance of a variable in a formula, while replacement is not uniform. When a symbol that ...
1
Context free grammar (cfg) satisfies your requirements, in a certain sense, when interpreted in a certain way.
(1) Among transformational theories, it is Minimal, since it has no transformations.
(2) It distinguishes X-bar types from X types in a systematic way, by (at least in my interpretation) not having X types as primitives. To be consistent with ...
1
Yes, in the Combinatory Categorial Grammar, type-raising X->T/(T\X) yields trivially ambiguous derivations such as:
X Y\X
---------------<
Y
vs
X Y\X
------->T
Y/(Y\X)
-------------->
Y
While this seems counterproductive, type-raising is invoked to allow a category to become a functor over a functor (see 'Argument ...
1
I'm not entirely sure what you mean by "basic" Lambek/categorial grammar, or by "basic objects". But you can certainly have multiple trees for the same string, at least in a bidirectional categorial grammar, i.e. a categorial grammar with two concatenation operations (\ and /).
A bidirectional CG:
The basic categories are n (for noun) and s (for sentence).
...
1
According to the Wikipedia definition of a metalanguage, a metalanguage is a language used to make statements about statements in another language. That is, it is a language designed to describe the constructs of another language.
Wikipedia then defines a metasyntax as the syntax or grammar of a given metalanguage.
Therefore, Backus-Naur Form (BNF) is a ...
1
If ambiguity is what the question is most concerned with, I think the short answer to the question is no: distinct structural analyses of an utterance almost always point to distinct meanings.
There are, however, numerous sources of ambiguity, syntax being one and lexical meaning being another. If the grammar does not have a way of acknowledging the cues ...
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