Implementing Lexical Functions in XLE

Linguistic collocations such as pay attention or heavy rain are semi-compositional expressions that require a special treatment in symbolic grammars for NLP. Within the Meaning-Text Theory framework, recurrent patterns of collocations have been identified and described via so-called "lexical functions". Building on our previous attempt at importing such lexical functions into LFG using glue semantics, in this paper, we show how a workable approximation to this can be implemented in XLE. We explore and compare three different approaches: using lexical functions in the f-structure, modelling collocations in the sigma-projection, and modelling them through transfer rules.