---
abstract: 'Phrase structure trees have a hierarchical structure. In many subjects, most notably in Taxonomy such tree structures have been studied using ultrametrics. Here syntactical hierarchical phrase trees are subject to a similar analysis, which is much simpler as the branching structure is more readily discernible and switched. The occurrence of hierarchical structure elsewhere in linguistics is mentioned. The phrase tree can be represented by a matrix and the elements of the matrix can be represented by triangles. The height at which branching occurs is not prescribed in previous syntactic models, but it is by using the ultrametric matrix. In other words the ultrametric approach gives a complete description of phrase trees, unlike previous approaches. The ambiguity of which branching height to choose, is resolved by postulating that branching occurs at the lowest height available. An ultrametric produces a measure of the complexity of sentences: presumably the complexity of sentences increases as a language is acquired so that this can be tested. All ultrametric triangles are equilateral or isoceles, here it is shown that \={X} structure implies that there are no equilateral triangles. Restricting attention to simple syntax a minimum ultrametric distance between lexical categories is calculated. This ultrametric distance is shown to be different than the matrix obtained from features. It is shown that the definition of {\sc c-command} can be replaced by an equivalent ultrametric definition. The new definition invokes a minimum distance between nodes and this is more aesthetically satisfying than previous varieties of definitions. From the new definition of {\sc c-command} follows a new definition of {\sc government}.'
altloc:
- http://arXiv.org/abs/cs.Cl/9810012
chapter: ~
commentary: ~
commref: ~
confdates: ~
conference: ~
confloc: ~
contact_email: ~
creators_id: []
creators_name:
- family: Roberts
given: Mark D.
honourific: ''
lineage: ''
date: 1995
date_type: published
datestamp: 2007-03-06
department: ~
dir: disk0/00/00/54/34
edit_lock_since: ~
edit_lock_until: ~
edit_lock_user: ~
editors_id: []
editors_name: []
eprint_status: archive
eprintid: 5434
fileinfo: /style/images/fileicons/application_pdf.png;/5434/1/udv6.pdf
full_text_status: public
importid: ~
institution: ~
isbn: ~
ispublished: unpub
issn: ~
item_issues_comment: []
item_issues_count: 0
item_issues_description: []
item_issues_id: []
item_issues_reported_by: []
item_issues_resolved_by: []
item_issues_status: []
item_issues_timestamp: []
item_issues_type: []
keywords: 'Phrase Trees, Ultrametricity, Syntax, Definitions of Government, Features, X bar structure.'
lastmod: 2011-03-11 08:56:47
latitude: ~
longitude: ~
metadata_visibility: show
note: |-
I will try to upload version 6 in pdf.
Still not published.
number: ~
pagerange: ~
pubdom: FALSE
publication: ~
publisher: ~
refereed: FALSE
referencetext: ~
relation_type: []
relation_uri: []
reportno: ~
rev_number: 12
series: ~
source: ~
status_changed: 2007-09-12 17:09:49
subjects:
- cog-psy
- comp-sci-speech
- ling-syntax
succeeds: 225
suggestions: ~
sword_depositor: ~
sword_slug: ~
thesistype: ~
title: Ultrametric Distance in Syntax
type: preprint
userid: 443
volume: ~