<s>
The	O
CO-OPN	B-Language
(	O
Concurrent	O
Object-Oriented	O
Petri	B-Operating_System
Nets	I-Operating_System
)	O
specification	B-Application
language	I-Application
is	O
based	O
on	O
both	O
algebraic	O
specifications	O
and	O
algebraic	B-Language
Petri	I-Language
nets	I-Language
formalisms	O
.	O
</s>
<s>
The	O
object-oriented	O
paradigm	O
has	O
been	O
adopted	O
,	O
which	O
means	O
that	O
a	O
CO-OPN	B-Language
specification	O
is	O
a	O
collection	O
of	O
objects	O
which	O
interact	O
concurrently	O
.	O
</s>
<s>
A	O
CO-OPN	B-Language
specification	O
consists	O
of	O
a	O
collection	O
of	O
two	O
different	O
modules	O
:	O
the	O
abstract	O
data	O
type	O
modules	O
and	O
the	O
object	O
modules	O
.	O
</s>
<s>
Algebraic	B-Language
Petri	I-Language
nets	I-Language
,	O
a	O
kind	O
of	O
high	O
level	O
nets	O
,	O
are	O
a	O
great	O
improvement	O
over	O
the	O
Petri	B-Operating_System
nets	I-Operating_System
,	O
i.e.	O
</s>
<s>
Petri	B-Operating_System
nets	I-Operating_System
tokens	O
are	O
replaced	O
with	O
data	O
structures	O
which	O
are	O
described	O
by	O
means	O
of	O
algebraic	O
abstract	O
data	O
types	O
.	O
</s>
<s>
To	O
develop	O
models	O
using	O
the	O
CO-OPN	B-Language
language	O
it	O
is	O
possible	O
to	O
use	O
the	O
COOPNBuilder	O
framework	O
that	O
is	O
an	O
environment	O
composed	O
of	O
a	O
set	O
of	O
tools	O
destinated	O
to	O
the	O
support	O
of	O
concurrent	O
software	O
development	O
based	O
on	O
the	O
CO-OPN	B-Language
language	O
.	O
</s>
