<s>
In	O
formal	O
language	O
theory	O
,	O
the	O
left	B-Application
corner	I-Application
of	O
a	O
production	O
rule	O
in	O
a	O
context-free	O
grammar	O
is	O
the	O
left-most	O
symbol	O
on	O
the	O
right	O
side	O
of	O
the	O
rule	O
.	O
</s>
<s>
For	O
example	O
,	O
in	O
the	O
rule	O
A	O
→	O
Xα	O
,	O
X	O
is	O
the	O
left	B-Application
corner	I-Application
.	O
</s>
<s>
The	O
left	B-Application
corner	I-Application
table	O
associates	O
to	O
a	O
symbol	O
all	O
possible	O
left	B-Application
corners	I-Application
for	O
that	O
symbol	O
,	O
and	O
the	O
left	B-Application
corners	I-Application
of	O
those	O
symbols	O
,	O
etc	O
.	O
</s>
<s>
the	O
left	B-Application
corner	I-Application
table	O
is	O
as	O
follows	O
.	O
</s>
<s>
Left	B-Application
corners	I-Application
are	O
used	O
to	O
add	O
bottom-up	O
filtering	O
to	O
a	O
top-down	B-Application
parser	I-Application
,	O
or	O
top-down	O
filtering	O
to	O
a	O
bottom-up	B-Application
parser	I-Application
.	O
</s>
