From a processing point of view, however, flexible categorial systems are problematic, since they introduce spurious ambiguity. In this paper, we present a flexible categorial grammar which makes extensive use of the product-operator, first introduced by Lambek (1958). The grammar has the property that for every reading of a sentence, a strictly left-branching derivation can be given. This leads to the definition of a subset of the grammar, for which the spurious ambiguity problem does not arise and efficient processing is possible. .
