Robin P. Fawcett is a Research Professor in Linguistics and Director of the Computational Linguistics Unit at the Cardiff School of English, Communication and Philosophy, Cardiff University, UK. M.A.K. Halliday is Emeritus Professor of Linguistics at the University of Sydney, Australia. Sydney Lamb is Emeritus Professor of Linguistics and Cognitive Science at Rice University in Texas, USA. Adam Makkai is Emeritus Professor of English and Linguistics at the University of Illinois at Chicago, USA.