<s>
rCOS	B-Application
stands	O
for	O
refinement	O
of	O
object	O
and	O
component	O
systems	O
.	O
</s>
<s>
It	O
is	O
a	O
formal	B-Architecture
method	I-Architecture
providing	O
component-based	B-Architecture
model-driven	B-Language
software	I-Language
development	I-Language
.	O
</s>
<s>
rCOS	B-Application
was	O
originally	O
developed	O
by	O
He	O
Jifeng	O
,	O
Zhiming	O
Liu	O
and	O
Xiaoshan	O
Li	O
at	O
UNU-IIST	O
in	O
Macau	O
,	O
and	O
consists	O
of	O
a	O
unified	O
multi-view	O
modeling	O
notation	O
with	O
a	O
theory	O
of	O
relational	O
semantic	O
and	O
graph-based	O
operational	O
semantics	O
,	O
a	O
refinement	B-Application
calculus	I-Application
and	O
tool	O
support	O
for	O
model	O
construction	O
,	O
model	O
analysis	O
and	O
verification	O
,	O
and	O
model	B-Language
transformations	I-Language
.	O
</s>
<s>
Model	B-Language
transformations	I-Language
automate	O
refinement	O
rules	O
and	O
design	O
patterns	O
and	O
generate	O
conditions	O
as	O
proof	O
obligations	O
.	O
</s>
<s>
rCOS	B-Application
support	O
multiple	O
dimensional	O
modeling	O
:	O
models	O
at	O
different	O
levels	O
of	O
abstraction	O
related	O
by	O
refinement	O
relations	O
,	O
hierarchy	O
of	O
compositions	O
of	O
components	O
,	O
and	O
models	O
of	O
different	O
views	O
of	O
the	O
system	O
(	O
interaction	B-Language
protocols	I-Language
of	O
components	O
,	O
reactive	O
behaviors	O
of	O
components	O
,	O
data	O
functionality	O
,	O
and	O
class	O
structures	O
and	O
data	O
types	O
)	O
.	O
</s>
