<s>
L-attributed	B-Application
grammars	I-Application
are	O
a	O
special	O
type	O
of	O
attribute	B-Application
grammars	I-Application
.	O
</s>
<s>
They	O
allow	O
the	O
attributes	O
to	O
be	O
evaluated	O
in	O
one	O
depth-first	O
left-to-right	O
traversal	O
of	O
the	O
abstract	B-Data_Structure
syntax	I-Data_Structure
tree	I-Data_Structure
.	O
</s>
<s>
As	O
a	O
result	O
,	O
attribute	O
evaluation	O
in	O
L-attributed	B-Application
grammars	I-Application
can	O
be	O
incorporated	O
conveniently	O
in	O
top-down	B-Application
parsing	I-Application
.	O
</s>
<s>
Special	O
types	O
of	O
compilers	B-Language
,	O
the	O
narrow	O
compilers	B-Language
,	O
are	O
based	O
on	O
some	O
form	O
of	O
L-attributed	B-Application
grammar	I-Application
.	O
</s>
<s>
These	O
are	O
a	O
strict	O
superset	O
of	O
S-attributed	B-Application
grammars	I-Application
.	O
</s>
