In this paper, we will motivate the application of specific rules of inference from the propositional calculus to natural language sentences. Specifically, we will analyse De Morgan’s laws, which pertain to the interaction of two central topics in syntactic research: negation and coordination. We will argue that the applicability of De Morgan’s laws to natural language structures can be derived from independently motivated operations of grammar and principles restricting the application of these operations. This has direct empirical consequences for the (...) hypothesised relations between natural language and logic. (shrink)

Proof-theoretic models of grammar are based on the view that an explicit characterization of a language comes in the form of the recursive enumeration of strings in that language. That recur-sive enumeration is carried out by a procedure which strongly generates a set of structural de-scriptions Σ and weakly generates a set of strings S; a grammar is thus a function that pairs an element of Σ with elements of S. Structural descriptions are obtained by means of Context-Free phrase structure (...) rules or via recursive combinatorics and structure is assumed to be uniform: binary branching trees all the way down. In this work we will analyse natural language constructions for which such a rigid conception of phrase structure is descriptively inadequate, and pro-pose a solution for the problem of phrase structure grammars assigning too much or too little structure to natural language strings: we propose that the grammar can oscillate between levels of computational complexity in local domains, which correspond to elementary trees in a lexicalised Tree Adjoining Grammar. (shrink)

In this article I consider some recent objections raised against the syntactic treatment of negation in English multiclausal structures, in particular what has been called NEGraising. I argue that the objections based on pronominalisation and ellipsis presented in the recent literature do pose a problem for syntactic accounts of the mechanisms of so-called NOT-transportation that rely on a rule of leftwards movement, as is customary in generative grammar. However, there is an alternative syntactic treatment that assumes that negation originates as (...) a higher predicate and is subject to a rule of lowering. I show that a syntactic theory of NOT-transportation is tenable and accounts for the problematic data if NEGraising is replaced, in the analysis of the cases considered here, by a rule of NEG-lowering. (shrink)