<s>
Flora-2	B-Language
is	O
an	O
open	B-License
source	I-License
semantic	O
rule-based	O
system	O
for	O
knowledge	O
representation	O
and	O
reasoning	O
.	O
</s>
<s>
The	O
language	O
of	O
the	O
system	O
is	O
derived	O
from	O
F-logic	B-Language
,	O
HiLog	B-Language
,	O
and	O
Transaction	B-Language
logic	I-Language
.	O
</s>
<s>
Being	O
based	O
on	O
F-logic	B-Language
and	O
HiLog	B-Language
implies	O
that	O
object-oriented	O
syntax	O
and	O
higher-order	O
representation	O
are	O
the	O
major	O
features	O
of	O
the	O
system	O
.	O
</s>
<s>
Flora-2	B-Language
also	O
supports	O
a	O
form	O
of	O
defeasible	O
reasoning	O
called	O
Logic	O
Programming	O
with	O
Defaults	O
and	O
Argumentation	O
Theories	O
(	O
LPDA	O
)	O
.	O
</s>
<s>
Flora-2	B-Language
relies	O
on	O
the	O
XSB	B-Language
system	I-Language
for	O
its	O
inference	O
engine	O
.	O
</s>
<s>
The	O
design	O
and	O
architecture	O
of	O
Flora-2	B-Language
are	O
described	O
in	O
a	O
number	O
of	O
works	O
.	O
</s>
<s>
Details	O
of	O
the	O
system	O
and	O
its	O
use	O
are	O
described	O
in	O
the	O
Flora-2	B-Language
User	O
's	O
Manual	O
.	O
</s>
<s>
Flora-2	B-Language
is	O
available	O
for	O
all	O
major	O
computing	O
platforms	O
,	O
including	O
Linux	B-Application
and	O
other	O
flavors	O
of	O
Unix	B-Application
,	O
Microsoft	B-Application
Windows	I-Application
,	O
and	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
.	O
</s>
<s>
Flora-2	B-Language
is	O
a	O
successor	O
to	O
the	O
Flora	O
system	O
(	O
1998	O
–	O
1999	O
)	O
and	O
incorporates	O
the	O
experience	O
gained	O
developing	O
and	O
using	O
the	O
original	O
Flora	O
system	O
.	O
</s>
<s>
The	O
Flora-2	B-Language
project	O
started	O
around	O
year	O
2000	O
by	O
Guizhen	O
Yang	O
and	O
Michael	O
Kifer	O
.	O
</s>
<s>
is	O
a	O
database	O
development	O
environment	O
similar	O
to	O
Access	B-Application
and	O
Base	B-Operating_System
.	O
</s>
<s>
is	O
a	O
module	O
which	O
adds	O
F-Logic	B-Language
to	O
Python	O
.	O
</s>
<s>
The	O
project	O
is	O
developing	O
an	O
extension	O
to	O
the	O
Perl	O
XSB	B-Language
interface	O
for	O
supporting	O
access	B-Application
to	O
Flora-2	B-Language
and	O
HiLog	B-Language
from	O
Perl	O
and	O
the	O
FreeKBS3	O
system	O
.	O
</s>
