<s>
The	O
bilinear	B-Algorithm
quadrilateral	I-Algorithm
element	I-Algorithm
,	O
also	O
known	O
as	O
the	O
Q4	B-Algorithm
element	I-Algorithm
,	O
is	O
a	O
type	O
of	O
element	O
used	O
in	O
finite	B-Application
element	I-Application
analysis	I-Application
which	O
is	O
used	O
to	O
approximate	O
in	O
a	O
2D	O
domain	O
the	O
exact	O
solution	O
to	O
a	O
given	O
differential	O
equation	O
.	O
</s>
