<s>
An	O
augmented	B-Application
transition	I-Application
network	I-Application
or	O
ATN	O
is	O
a	O
type	O
of	O
graph	O
theoretic	O
structure	O
used	O
in	O
the	O
operational	O
definition	O
of	O
formal	O
languages	O
,	O
used	O
especially	O
in	O
parsing	B-Language
relatively	O
complex	O
natural	O
languages	O
,	O
and	O
having	O
wide	O
application	O
in	O
artificial	B-Application
intelligence	I-Application
.	I-Application
</s>
<s>
ATNs	B-Application
build	O
on	O
the	O
idea	O
of	O
using	O
finite	B-Architecture
state	I-Architecture
machines	I-Architecture
(	O
Markov	O
model	O
)	O
to	O
parse	B-Language
sentences	O
.	O
</s>
<s>
Woods	O
in	O
"	O
Transition	O
Network	O
Grammars	O
for	O
Natural	O
Language	O
Analysis	O
"	O
claims	O
that	O
by	O
adding	O
a	O
recursive	O
mechanism	O
to	O
a	O
finite	B-Architecture
state	I-Architecture
model	O
,	O
parsing	B-Language
can	O
be	O
achieved	O
much	O
more	O
efficiently	O
.	O
</s>
<s>
A	O
grammatically	O
correct	O
sentence	O
is	O
parsed	B-Language
by	O
reaching	O
a	O
final	O
state	O
in	O
any	O
state	O
graph	O
.	O
</s>
<s>
By	O
the	O
use	O
of	O
recursion	O
,	O
ATNs	B-Application
solve	O
this	O
inefficiency	O
by	O
postponing	O
decisions	O
until	O
more	O
is	O
known	O
about	O
a	O
sentence	O
.	O
</s>
