... as defined by Kaplan and Zaenan [3] and Kaplan and Maxwell [2]. In this paper, we relate this characterization to that provided by Tree ~,djoining Grammars (TAG), showing a di- rect correspondence ... adjoining. Consider the adjoining of/~ at the node marked with * in a. The subtree of a under the node marked with * is excised, and/ 3 is inserted in its place. Finally, the excised subtree is ... unify t, with troot, and b, with b/oot. In fact, this adjoining -is permissible only if t.oo~ and t. are compatible and so are b/oot and b~. If we do not adjoin at the node, 7, then...