We define and study a calculus of discontinuity, a version of displacement calculus, which is a logic of segmented strings in exactly the same sense that the Lambek calculus is a ...
The Lambek calculus L provides a foundation for categorial grammar in the form of a logic of concatenation. But natural language is characterized by dependencies which may also be...
In this paper we prove that the derivability problems for productfree Lambek calculus and product-free Lambek calculus allowing empty premises are NP-complete. Also we introduce a...
The Lambek-Grishin calculus LG is the symmetric extension of the non-associative Lambek calculus NL. In this paper we prove that the derivability problem for LG is NP-complete.