<s>
Regulated	B-Application
rewriting	I-Application
is	O
a	O
specific	O
area	O
of	O
formal	O
languages	O
studying	O
grammatical	O
systems	O
which	O
are	O
able	O
to	O
take	O
some	O
kind	O
of	O
control	O
over	O
the	O
production	O
applied	O
in	O
a	O
derivation	O
step	O
.	O
</s>
<s>
For	O
this	O
reason	O
,	O
the	O
grammatical	O
systems	O
studied	O
in	O
Regulated	B-Application
Rewriting	I-Application
theory	O
are	O
also	O
called	O
"	O
Grammars	O
with	O
Controlled	O
Derivations	O
"	O
.	O
</s>
<s>
Besides	O
there	O
are	O
other	O
grammars	O
with	O
regulated	B-Application
rewriting	I-Application
,	O
the	O
four	O
cited	O
above	O
are	O
good	O
examples	O
of	O
how	O
to	O
extend	O
context-free	O
grammars	O
with	O
some	O
kind	O
of	O
control	O
mechanism	O
to	O
obtain	O
a	O
Turing	B-Architecture
machine	I-Architecture
powerful	O
grammatical	O
device	O
.	O
</s>
