<s>
LR-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
on	O
LR	B-Application
parsing	I-Application
.	O
</s>
<s>
As	O
a	O
result	O
,	O
attribute	O
evaluation	O
in	O
LR-attributed	B-Application
grammars	I-Application
can	O
be	O
incorporated	O
conveniently	O
in	O
bottom-up	O
parsing	O
.	O
</s>
<s>
zyacc	O
is	O
based	O
on	O
LR-attributed	B-Application
grammars	I-Application
.	O
</s>
<s>
They	O
are	O
a	O
subset	O
of	O
the	O
L-attributed	B-Application
grammars	I-Application
,	O
where	O
the	O
attributes	O
can	O
be	O
evaluated	O
in	O
one	O
left-to-right	O
traversal	O
of	O
the	O
abstract	O
syntax	O
tree	O
.	O
</s>
<s>
They	O
are	O
a	O
superset	O
of	O
the	O
S-attributed	B-Application
grammars	I-Application
,	O
which	O
allow	O
only	O
synthesized	O
attributes	O
.	O
</s>
