[Attempto] Regarding APE

[Joshua TAYLOR]

On Fri, Mar 16, 2012 at 10:44 AM, Ananya Poddar <ananya0112 at gmail.com> wrote:
> Hello Sir.
>      I have been working with the APE(Ace Parser) engine in the site, n Im
> making use of "syntax " during my sentence construction.
>     A sentence like "A sky's color is blue" is interepreted such that color
> is given by 'nbar'. Can you please explain what nbar stands for?
>     Thank you.

Disclaimer: I'm not associated with the Attempto group, but the
question looked interesting, so I decided to take a look. From the
Wikipedia page on X-bar theory [1]:

"The letter X is used to signify an arbitrary lexical category (part
of speech); when analyzing a specific utterance, specific categories
are assigned. Thus, the X may become an N for noun, a V for verb, an A
for adjective, or a P for preposition. The term X-bar is derived from
the notation representing this new structure. Certain structures are
represented by X (an X with an overbar). Because this is difficult to
typeset, this is often written as X′, using the prime symbol. In
English, however, this is still read as "X bar". The notation XP
stands for X Phrase, and is equivalent to X-bar-bar (X with a double
overbar), written X″, usually read aloud as X double bar."

There are some parse trees on that page that use N with an overbar
(hence, nbar), as well.

[1] http://en.wikipedia.org/wiki/X-bar_theory

-- 
Joshua Taylor, http://www.cs.rpi.edu/~tayloj/