<s>
NuSMV	B-Language
is	O
a	O
reimplementation	O
and	O
extension	O
of	O
SMV	O
symbolic	O
model	B-Application
checker	I-Application
,	O
the	O
first	O
model	B-Application
checking	I-Application
tool	O
based	O
on	O
Binary	B-Application
Decision	I-Application
Diagrams	I-Application
(	O
BDDs	O
)	O
.	O
</s>
<s>
The	O
tool	O
has	O
been	O
designed	O
as	O
an	O
open	B-Architecture
architecture	I-Architecture
for	O
model	B-Application
checking	I-Application
.	O
</s>
<s>
NuSMV	B-Language
has	O
been	O
developed	O
as	O
a	O
joint	O
project	O
between	O
ITC-IRST	O
(	O
Istituto	O
Trentino	O
di	O
Cultura	O
in	O
Trento	O
,	O
Italy	O
)	O
,	O
Carnegie	O
Mellon	O
University	O
,	O
the	O
University	O
of	O
Genoa	O
and	O
the	O
University	O
of	O
Trento	O
.	O
</s>
<s>
NuSMV	B-Language
2	I-Language
,	O
version	O
2	O
of	O
NuSMV	B-Language
,	O
inherits	O
all	O
the	O
functionalities	O
of	O
NuSMV	B-Language
.	O
</s>
<s>
Furthermore	O
,	O
it	O
combines	O
BDD-based	O
model	B-Application
checking	I-Application
with	O
SAT-based	O
model	B-Application
checking	I-Application
.	O
</s>
<s>
NuSMV	B-Language
supports	O
the	O
analysis	O
of	O
specifications	O
expressed	O
in	O
CTL	O
and	O
LTL	O
.	O
</s>
<s>
User	O
interaction	O
is	O
performed	O
with	O
a	O
textual	O
interface	O
,	O
as	O
well	O
as	O
in	O
batch	B-General_Concept
mode	I-General_Concept
.	O
</s>
<s>
The	O
interaction	O
shell	O
of	O
NuSMV	B-Language
is	O
activated	O
from	O
the	O
system	O
prompt	O
as	O
follows	O
:	O
</s>
<s>
NuSMV	B-Language
first	O
tries	O
to	O
read	O
and	O
execute	O
commands	O
from	O
an	O
initialization	O
file	O
if	O
such	O
file	O
exists	O
and	O
is	O
readable	O
unless	O
-s	O
is	O
passed	O
on	O
the	O
command	O
line	O
.	O
</s>
<s>
File	O
master.nusmvrc	O
is	O
looked	O
for	O
in	O
directory	O
defined	O
in	O
environment	O
variable	O
NUSMV	B-Language
_LIBRARY_PATH	O
or	O
in	O
default	O
library	O
path	O
if	O
no	O
such	O
variable	O
is	O
defined	O
.	O
</s>
<s>
When	O
initialization	O
phase	O
is	O
completed	O
the	O
NuSMV	B-Language
shell	O
is	O
displayed	O
and	O
the	O
system	O
is	O
now	O
ready	O
to	O
execute	O
user	O
commands	O
.	O
</s>
<s>
A	O
NuSMV	B-Language
command	O
usually	O
consists	O
of	O
a	O
command	O
name	O
and	O
arguments	O
to	O
the	O
invoked	O
command	O
.	O
</s>
<s>
It	O
is	O
possible	O
to	O
make	O
NuSMV	B-Language
read	O
and	O
execute	O
a	O
sequence	O
of	O
commands	O
from	O
a	O
file	O
,	O
through	O
the	O
command	O
line	O
option	O
-source	O
:	O
</s>
<s>
When	O
the	O
-int	O
option	O
is	O
not	O
specified	O
,	O
NuSMV	B-Language
runs	O
as	O
a	O
batch	B-General_Concept
program	I-General_Concept
,	O
which	O
is	O
with	O
the	O
form	O
as	O
follows	O
:	O
</s>
<s>
NuSMV	B-Language
can	O
be	O
used	O
to	O
check	O
whether	O
the	O
predefined	O
LTL	O
or	O
CTL	O
constraints	O
holds	O
for	O
the	O
defined	O
model	O
.	O
</s>
<s>
However	O
,	O
if	O
the	O
specification	O
fails	O
at	O
some	O
state	O
,	O
NuSMV	B-Language
will	O
return	O
a	O
full	O
trace	O
of	O
execution	O
showing	O
how	O
it	O
fails	O
.	O
</s>
