<s>
In	O
linguistics	O
,	O
center	B-General_Concept
embedding	I-General_Concept
is	O
the	O
process	O
of	O
embedding	O
a	O
phrase	O
in	O
the	O
middle	O
of	O
another	O
phrase	O
of	O
the	O
same	O
type	O
.	O
</s>
<s>
This	O
often	O
leads	O
to	O
difficulty	O
with	O
parsing	B-Language
which	O
would	O
be	O
difficult	O
to	O
explain	O
on	O
grammatical	O
grounds	O
alone	O
.	O
</s>
<s>
In	O
theories	O
of	O
natural	O
language	O
parsing	B-Language
,	O
the	O
difficulty	O
with	O
multiple	O
center	B-General_Concept
embedding	I-General_Concept
is	O
thought	O
to	O
arise	O
from	O
limitations	O
of	O
the	O
human	O
short	O
term	O
memory	O
.	O
</s>
<s>
In	O
order	O
to	O
process	O
multiple	O
center	B-General_Concept
embeddings	I-General_Concept
,	O
we	O
have	O
to	O
store	O
many	O
subjects	O
in	O
order	O
to	O
connect	O
them	O
to	O
their	O
predicates	O
.	O
</s>
<s>
An	O
interesting	O
theoretical	O
point	O
is	O
that	O
sentences	O
with	O
multiple	O
center	B-General_Concept
embedding	I-General_Concept
are	O
grammatical	O
,	O
but	O
unacceptable	O
.	O
</s>
<s>
Some	O
researchers	O
(	O
such	O
as	O
Peter	O
Reich	O
)	O
came	O
up	O
with	O
theories	O
that	O
though	O
single	O
center	B-General_Concept
embedding	I-General_Concept
is	O
acceptable	O
(	O
as	O
in	O
"	O
the	O
man	O
that	O
boy	O
kicked	O
is	O
a	O
friend	O
of	O
mine	O
"	O
)	O
,	O
double	O
center	B-General_Concept
embedding	I-General_Concept
is	O
not	O
.	O
</s>
<s>
Center	B-General_Concept
embedding	I-General_Concept
is	O
the	O
focus	O
of	O
a	O
science	O
fiction	O
novel	O
,	O
Ian	O
Watson	O
's	O
The	O
Embedding	O
,	O
and	O
plays	O
a	O
part	O
in	O
Ted	O
Chiang	O
's	O
Story	O
of	O
Your	O
Life	O
.	O
</s>
<s>
Center	B-General_Concept
embedding	I-General_Concept
(	O
abbreviated	O
"	O
C	O
"	O
or	O
"	O
c	O
"	O
)	O
contains	O
words	O
of	O
the	O
superordinate	O
clause	O
on	O
the	O
left	O
and	O
the	O
right	O
of	O
the	O
sub-clauses	O
.	O
</s>
<s>
Multiple	O
center	B-General_Concept
embedding	I-General_Concept
of	O
the	O
same	O
type	O
of	O
clause	O
is	O
called	O
self-embedding	O
.	O
</s>
<s>
The	O
rule	O
of	O
recursion	O
is	O
how	O
we	O
come	O
to	O
center	B-General_Concept
embedding	I-General_Concept
by	O
embedding	O
one	O
sentence	O
within	O
another	O
sentence	O
.	O
</s>
<s>
Linguists	O
say	O
that	O
center	B-General_Concept
embedding	I-General_Concept
could	O
go	O
on	O
forever	O
and	O
technically	O
be	O
grammatically	O
correct	O
.	O
</s>
