Abstract TAGs were recently shown not to be closed under strong lexicalization but to be strongly lexicalizable by context-free tree grammars of rank 2. This paper presents an alternative lexicalization procedure that builds on an earlier generalization of TAGs to multi-dimensional trees. A previous theorem that every Tree Substitution grammar is strongly lexicalized by a corresponding TAG is lifted to higher dimensions to show that for every $d$-dimensional TAG there exists a $(d+1)$-dimensional TAG that strongly lexicalizes it. A similar lifting reveals that $d$-dimensional TAGs are not closed under strong lexicalization, so for arbitrary TAGs an increase in dimensionality is an unavoidable consequence of strong lexicalization.
@Misc{DeSantoEtAl16TAGtalk,
author = {De Santo, Aniello and Aks\"{e}nova, Al\"{e}na and Graf, Thomas},
title = {An Alternate View on Strong Lexicalization in {TAG}},
year = {2016},
note = {Slides of a talk given at the 12th International Workshop on Tree Adjoining Grammars and Related Formalisms, June 29 -- July 1, Düsseldorf, Germany}
}