Dominance

Revision as of 15:00, 24 March 2010

Dominance is the relation between two nodes in a tree structure. A node "dominates" another node if it is above it in the tree (it is a parent, grandparent, etc). In the UNL^arium framework, dominance is used to represent the structure of maximal projections and, therefore, to state the degree of adjacency (i.e., the order) of constituents in relation to the head. Dominance is represented in the dictionary, in case of compound words that do not follow general dominance rules, or in the grammar, otherwise. Dominance is not represented in UNL.

C-command

In the UNL^arium framework, syntactic relations are described in terms of a general tree structure: the X-bar, depicted below.

    XP
   / \
spec  XB
     / \
    XB  adjt
   / \
  X   comp

In the X-bar structure above, the node XP dominates all other nodes; the higher XB dominates the nodes adjt, lower XB, comp and X (head); the lower XB dominates the nodes comp and X; and the nodes spec, adjt, comp and X do not dominate any node.

The structure above, however, is only a model and it may vary a lot: it may have more than one complement (as in ditransitive constructions such as "I gave John the keys"), more than one adjunct ("He worked in the office from 6:00 AM to 6:00 PM during the last year"), complement-adjunct inversions, such as in "bring home the bacon", etc. These modifications affect mainly the structure of the intermediary projection XB, which may indeed assume several different configurations, as indicated below:

    XP
   / \
spec  XB
     / \
    XB  adjt
   / \
  X   comp

    XP
   / \
spec  XB
     / \
    XB  comp
   / \
  X   comp

    XP
   / \
spec  XB
     / \
    XB  adjt
   / \
  X   adjt

    XP
   / \
spec  XB
     / \
    XB  comp
   / \
  X   adjt

    XP
   / \
spec XB 
     / \
    XB  adjt
   / \
  XB  adjt
 / \
X comp

       XP
      / \
   spec XB 
       / \
      XB  adjt
     / \
    XB  adjt
   / \
  XB comp
 / \
X  comp

In order to describe such structures, the UNL^arium makes use of a well-established syntactic notion: c-command.

A c-commands B if and only if neither A nor B dominates the other, and the lowest branching node that dominates A also dominates B. 

This means that, in the first tree, X c-commands comp, the lower XB c-commands adjt, and the higher XB c-commands spec. C-command defines, thus, a sort of relation of adjacency between syntactic structures, and it is used to guide the process of generating complex sentences and multi-word expressions.

Dictionary

Grammar