<s>
SNePS	B-Language
is	O
a	O
knowledge	O
representation	O
,	O
reasoning	O
,	O
and	O
acting	O
(	O
KRRA	O
)	O
system	O
developed	O
and	O
maintained	O
by	O
Stuart	O
C	O
.	O
Shapiro	O
and	O
colleagues	O
at	O
the	O
State	O
University	O
of	O
New	O
York	O
at	O
Buffalo	O
.	O
</s>
<s>
SNePS	B-Language
is	O
simultaneously	O
a	O
logic-based	O
,	O
frame-based	O
,	O
and	O
network-based	O
KRRA	O
system	O
.	O
</s>
<s>
It	O
uses	O
an	O
assertional	O
model	O
of	O
knowledge	O
,	O
in	O
that	O
a	O
SNePS	B-Language
knowledge	O
base	O
(	O
KB	O
)	O
consists	O
of	O
a	O
set	O
of	O
assertions	O
(	O
propositions	O
)	O
about	O
various	O
entities	O
.	O
</s>
<s>
SNePS	B-Language
has	O
three	O
styles	O
of	O
inference	O
:	O
formula-based	O
,	O
derived	O
from	O
its	O
logic-based	O
personality	O
;	O
slot-based	O
,	O
derived	O
from	O
its	O
frame-based	O
personality	O
;	O
and	O
path-based	O
,	O
derived	O
from	O
its	O
network-based	O
personality	O
.	O
</s>
<s>
SNePS	B-Language
may	O
be	O
used	O
as	O
a	O
stand-alone	O
KRR	O
system	O
.	O
</s>
<s>
It	O
has	O
also	O
been	O
used	O
,	O
along	O
with	O
its	O
integrated	O
acting	O
component	O
,	O
to	O
implement	O
the	O
mind	O
of	O
intelligent	B-General_Concept
agents	I-General_Concept
(	O
cognitive	B-General_Concept
robots	I-General_Concept
)	O
,	O
in	O
accord	O
with	O
the	O
GLAIR	O
agent	B-General_Concept
architecture	I-General_Concept
(	O
a	O
layered	O
cognitive	B-General_Concept
architecture	I-General_Concept
)	O
.	O
</s>
<s>
The	O
SNePS	B-Language
Research	O
Group	O
often	O
calls	O
its	O
agents	O
Cassie	O
.	O
</s>
<s>
As	O
a	O
logic-based	O
system	O
,	O
a	O
SNePS	B-Language
KB	O
consists	O
of	O
a	O
set	O
of	O
terms	O
,	O
and	O
functions	O
and	O
formulas	O
over	O
those	O
terms	O
.	O
</s>
<s>
The	O
set	O
of	O
logical	O
connectives	O
and	O
quantifiers	B-Language
extends	O
the	O
usual	O
set	O
used	O
by	O
first-order	O
logics	O
,	O
all	O
taking	O
one	O
or	O
more	O
arbitrarily-sized	O
sets	O
of	O
arguments	O
.	O
</s>
<s>
In	O
accord	O
with	O
the	O
intended	O
use	O
of	O
SNePS	B-Language
to	O
represent	O
the	O
mind	O
of	O
a	O
natural-language-competent	O
intelligent	B-General_Concept
agent	I-General_Concept
,	O
propositions	O
are	O
first-class	O
entities	O
of	O
the	O
intended	O
domain	O
,	O
so	O
formulas	O
are	O
actually	O
proposition-denoting	O
functional	O
terms	O
.	O
</s>
<s>
SNePSLOG	O
,	O
the	O
input-output	O
language	O
of	O
the	O
logic-based	O
face	O
of	O
SNePS	B-Language
,	O
looks	O
like	O
a	O
naive	O
logic	O
in	O
that	O
function	O
symbols	O
(	O
including	O
"	O
predicates	O
"	O
)	O
,	O
and	O
formulas	O
(	O
actually	O
proposition-denoting	O
terms	O
)	O
may	O
be	O
the	O
arguments	O
of	O
functions	O
and	O
may	O
be	O
quantified	O
over	O
.	O
</s>
<s>
The	O
underlying	O
SNePS	B-Language
,	O
however	O
,	O
is	O
a	O
first	O
order	O
logic	O
,	O
with	O
the	O
user	O
's	O
function	O
symbols	O
and	O
formulas	O
reified	O
.	O
</s>
<s>
Formula-based	O
inference	O
is	O
implemented	O
as	O
a	O
natural-deduction-style	O
inference	O
engine	O
in	O
which	O
there	O
are	O
introduction	O
and	O
elimination	O
rules	O
for	O
the	O
connectives	O
and	O
quantifiers	B-Language
.	O
</s>
<s>
SNePS	B-Language
formula-based	O
inference	O
is	O
sound	O
but	O
not	O
complete	O
,	O
as	O
rules	O
of	O
inference	O
that	O
are	O
less	O
useful	O
for	O
natural	B-General_Concept
language	I-General_Concept
understanding	I-General_Concept
and	O
commonsense	O
reasoning	O
have	O
not	O
been	O
implemented	O
.	O
</s>
<s>
A	O
proposition-denoting	O
term	O
in	O
a	O
SNePS	B-Language
KB	O
might	O
or	O
might	O
not	O
be	O
"	O
asserted	O
"	O
,	O
that	O
is	O
,	O
treated	O
as	O
true	O
in	O
the	O
KB	O
.	O
</s>
<s>
The	O
SNePS	B-Language
logic	O
is	O
a	O
paraconsistent	O
version	O
of	O
relevance	O
logic	O
,	O
so	O
that	O
a	O
contradiction	O
does	O
not	O
imply	O
anything	O
whatsoever	O
.	O
</s>
<s>
Nevertheless	O
,	O
SNeBR	O
,	O
the	O
SNePS	B-Language
Belief	O
Revision	O
subsystem	O
,	O
will	O
notice	O
any	O
explicit	O
contradiction	O
and	O
engage	O
the	O
user	O
in	O
a	O
dialogue	O
to	O
repair	O
it	O
.	O
</s>
<s>
As	O
a	O
frame-based	O
system	O
,	O
every	O
SNePS	B-Language
functional	O
term	O
(	O
including	O
proposition-valued	O
terms	O
)	O
is	O
represented	O
by	O
a	O
frame	O
with	O
slots	O
and	O
fillers	O
.	O
</s>
<s>
SNePSUL	O
,	O
the	O
SNePS	B-Language
User	O
Language	O
is	O
an	O
input-output	O
language	O
for	O
interacting	O
with	O
SNePS	B-Language
in	O
its	O
guise	O
as	O
a	O
frame-based	O
system	O
.	O
</s>
<s>
As	O
a	O
network-based	O
system	O
,	O
SNePS	B-Language
is	O
a	O
propositional	O
semantic	O
network	O
,	O
</s>
<s>
the	O
SNePS	B-Language
logic	O
,	O
and	O
they	O
range	O
over	O
nodes	O
,	O
and	O
only	O
over	O
nodes	O
.	O
</s>
<s>
are	O
not	O
represented	O
in	O
SNePS	B-Language
.	O
</s>
<s>
SNIP	O
,	O
the	O
SNePS	B-Language
Inference	O
Package	O
,	O
provides	O
the	O
rules	O
of	O
inference	O
with	O
which	O
SNePS	B-Language
deduces	O
new	O
assertions	O
from	O
an	O
existing	O
KB	O
.	O
</s>
<s>
SNeBR	O
,	O
the	O
SNePS	B-Language
Belief	O
Revision	O
package	O
,	O
is	O
a	O
component	O
of	O
SNePS	B-Language
that	O
detects	O
when	O
the	O
KB	O
contains	O
contradictory	O
beliefs	O
.	O
</s>
<s>
SNeRE	O
,	O
the	O
SNePS	B-Language
Rational	O
Engine	O
,	O
provides	O
an	O
acting	O
executive	O
and	O
a	O
set	O
of	O
frames	O
for	O
building	O
up	O
complex	O
acts	O
and	O
plans	O
from	O
a	O
set	O
of	O
system-defined	O
and	O
user-defined	O
primitive	O
actions	O
.	O
</s>
<s>
SNaLPS	O
,	O
the	O
SNePS	B-Language
Natural	B-Language
Language	I-Language
Processing	I-Language
System	O
,	O
consists	O
of	O
a	O
Generalized	O
Augmented	B-Application
Transition	I-Application
Network	I-Application
Grammar	O
interpreter	O
and	O
an	O
English	O
morphological	O
analyzer	O
and	O
synthesizer	O
so	O
that	O
natural	B-General_Concept
language	I-General_Concept
understanding	I-General_Concept
and	O
generation	O
may	O
be	O
provided	O
for	O
SNePS-based	O
agents	O
.	O
</s>
<s>
cognitive	B-General_Concept
robotics	I-General_Concept
.	O
</s>
<s>
SNePS	B-Language
is	O
implemented	O
as	O
a	O
platform-independent	O
system	O
in	O
Common	B-Language
Lisp	I-Language
and	O
is	O
freely	O
available	O
.	O
</s>
