<s>
Aspen	B-Application
HYSYS	I-Application
(	O
or	O
simply	O
HYSYS	O
)	O
is	O
a	O
chemical	B-Application
process	I-Application
simulator	I-Application
currently	O
developed	O
by	O
AspenTech	O
used	O
to	O
mathematically	O
model	O
chemical	O
processes	O
,	O
from	O
unit	O
operations	O
to	O
full	O
chemical	O
plants	O
and	O
refineries	O
.	O
</s>
