<s>
In	O
information	B-General_Concept
technology	I-General_Concept
a	O
reasoning	B-Application
system	I-Application
is	O
a	O
software	O
system	O
that	O
generates	O
conclusions	O
from	O
available	O
knowledge	O
using	O
logical	O
techniques	O
such	O
as	O
deduction	O
and	O
induction	O
.	O
</s>
<s>
Reasoning	B-Application
systems	I-Application
play	O
an	O
important	O
role	O
in	O
the	O
implementation	O
of	O
artificial	B-Application
intelligence	I-Application
and	O
knowledge-based	B-General_Concept
systems	I-General_Concept
.	O
</s>
<s>
By	O
the	O
everyday	O
usage	O
definition	O
of	O
the	O
phrase	O
,	O
all	O
computer	O
systems	O
are	O
reasoning	B-Application
systems	I-Application
in	O
that	O
they	O
all	O
automate	O
some	O
type	O
of	O
logic	O
or	O
decision	O
.	O
</s>
<s>
In	O
typical	O
use	O
in	O
the	O
Information	B-General_Concept
Technology	I-General_Concept
field	O
however	O
,	O
the	O
phrase	O
is	O
usually	O
reserved	O
for	O
systems	O
that	O
perform	O
more	O
complex	O
kinds	O
of	O
reasoning	O
.	O
</s>
<s>
Reasoning	B-Application
systems	I-Application
come	O
in	O
two	O
modes	O
:	O
interactive	O
and	O
batch	O
processing	O
.	O
</s>
<s>
Reasoning	B-Application
systems	I-Application
have	O
a	O
wide	O
field	O
of	O
application	O
that	O
includes	O
scheduling	B-Application
,	O
business	B-Application
rule	I-Application
processing	I-Application
,	O
problem	O
solving	O
,	O
complex	B-Operating_System
event	I-Operating_System
processing	I-Operating_System
,	O
intrusion	O
detection	O
,	O
predictive	B-General_Concept
analytics	I-General_Concept
,	O
robotics	O
,	O
computer	B-Application
vision	I-Application
,	O
and	O
natural	B-Language
language	I-Language
processing	I-Language
.	O
</s>
<s>
The	O
first	O
reasoning	B-Application
systems	I-Application
were	O
theorem	B-Application
provers	I-Application
,	O
systems	O
that	O
represent	O
axioms	O
and	O
statements	O
in	O
First	O
Order	O
Logic	O
and	O
then	O
use	O
rules	O
of	O
logic	O
such	O
as	O
modus	O
ponens	O
to	O
infer	O
new	O
statements	O
.	O
</s>
<s>
Another	O
early	O
type	O
of	O
reasoning	B-Application
system	I-Application
were	O
general	O
problem	O
solvers	O
.	O
</s>
<s>
Another	O
example	O
general	O
problem	O
solver	O
was	O
the	O
SOAR	B-Architecture
family	O
of	O
systems	O
.	O
</s>
<s>
In	O
practice	O
these	O
theorem	B-Application
provers	I-Application
and	O
general	O
problem	O
solvers	O
were	O
seldom	O
useful	O
for	O
practical	O
applications	O
and	O
required	O
specialized	O
users	O
with	O
knowledge	O
of	O
logic	O
to	O
utilize	O
.	O
</s>
<s>
The	O
first	O
practical	O
application	O
of	O
automated	O
reasoning	O
were	O
expert	B-Application
systems	I-Application
.	O
</s>
<s>
Expert	B-Application
systems	I-Application
focused	O
on	O
much	O
more	O
well	O
defined	O
domains	O
than	O
general	O
problem	O
solving	O
such	O
as	O
medical	O
diagnosis	O
or	O
analyzing	O
faults	O
in	O
an	O
aircraft	O
.	O
</s>
<s>
Expert	B-Application
systems	I-Application
also	O
focused	O
on	O
more	O
limited	O
implementations	O
of	O
logic	O
.	O
</s>
<s>
Focusing	O
on	O
a	O
specific	O
domain	O
and	O
allowing	O
only	O
a	O
restricted	O
subset	O
of	O
logic	O
improved	O
the	O
performance	O
of	O
such	O
systems	O
so	O
that	O
they	O
were	O
practical	O
for	O
use	O
in	O
the	O
real	O
world	O
and	O
not	O
merely	O
as	O
research	O
demonstrations	O
as	O
most	O
previous	O
automated	B-Application
reasoning	I-Application
systems	I-Application
had	O
been	O
.	O
</s>
<s>
The	O
engine	O
used	O
for	O
automated	O
reasoning	O
in	O
expert	B-Application
systems	I-Application
were	O
typically	O
called	O
inference	O
engines	O
.	O
</s>
<s>
Those	O
used	O
for	O
more	O
general	O
logical	O
inferencing	O
are	O
typically	O
called	O
theorem	B-Application
provers	I-Application
.	O
</s>
<s>
With	O
the	O
rise	O
in	O
popularity	O
of	O
expert	B-Application
systems	I-Application
many	O
new	O
types	O
of	O
automated	O
reasoning	O
were	O
applied	O
to	O
diverse	O
problems	O
in	O
government	O
and	O
industry	O
.	O
</s>
<s>
Some	O
such	O
as	O
case-based	O
reasoning	O
were	O
off	O
shoots	O
of	O
expert	B-Application
systems	I-Application
research	O
.	O
</s>
<s>
Others	O
such	O
as	O
constraint	O
satisfaction	O
algorithms	O
were	O
also	O
influenced	O
by	O
fields	O
such	O
as	O
decision	O
technology	O
and	O
linear	B-Algorithm
programming	I-Algorithm
.	O
</s>
<s>
The	O
term	O
reasoning	B-Application
system	I-Application
can	O
be	O
used	O
to	O
apply	O
to	O
just	O
about	O
any	O
kind	O
of	O
sophisticated	O
decision	B-Application
support	I-Application
system	I-Application
as	O
illustrated	O
by	O
the	O
specific	O
areas	O
described	O
below	O
.	O
</s>
<s>
However	O
,	O
the	O
most	O
common	O
use	O
of	O
the	O
term	O
reasoning	B-Application
system	I-Application
implies	O
the	O
computer	O
representation	O
of	O
logic	O
.	O
</s>
<s>
Most	O
reasoning	B-Application
systems	I-Application
implement	O
variations	O
of	O
propositional	O
and	O
symbolic	O
(	O
predicate	O
)	O
logic	O
.	O
</s>
<s>
Reasoning	B-Application
systems	I-Application
may	O
explicitly	O
implement	O
additional	O
logic	O
types	O
(	O
e.g.	O
,	O
modal	O
,	O
deontic	O
,	O
temporal	O
logics	O
)	O
.	O
</s>
<s>
However	O
,	O
many	O
reasoning	B-Application
systems	I-Application
implement	O
imprecise	O
and	O
semi-formal	O
approximations	O
to	O
recognised	O
logic	O
systems	O
.	O
</s>
<s>
These	O
systems	O
typically	O
support	O
a	O
variety	O
of	O
procedural	O
and	O
semi-declarative	O
techniques	O
in	O
order	O
to	O
model	O
different	O
reasoning	O
strategies	O
.	O
</s>
<s>
Many	O
reasoning	B-Application
systems	I-Application
employ	O
deductive	O
reasoning	O
to	O
draw	O
inferences	O
from	O
available	O
knowledge	O
.	O
</s>
<s>
Although	O
reasoning	B-Application
systems	I-Application
widely	O
support	O
deductive	O
inference	O
,	O
some	O
systems	O
employ	O
abductive	O
,	O
inductive	O
,	O
defeasible	O
and	O
other	O
types	O
of	O
reasoning	O
.	O
</s>
<s>
Heuristics	B-Algorithm
may	O
also	O
be	O
employed	O
to	O
determine	O
acceptable	O
solutions	O
to	O
intractable	O
problems	O
.	O
</s>
<s>
Reasoning	B-Application
systems	I-Application
may	O
employ	O
the	O
closed	B-Application
world	I-Application
assumption	I-Application
(	O
CWA	O
)	O
or	O
open	B-Application
world	I-Application
assumption	I-Application
(	O
OWA	O
)	O
.	O
</s>
<s>
The	O
OWA	O
is	O
often	O
associated	O
with	O
ontological	B-Language
knowledge	O
representation	O
and	O
the	O
Semantic	O
Web	O
.	O
</s>
<s>
As	O
well	O
as	O
logical	O
or	O
bitwise	O
complement	O
,	O
systems	O
may	O
support	O
existential	O
forms	O
of	O
strong	O
and	O
weak	B-Application
negation	I-Application
including	O
negation-as-failure	B-Application
and	O
‘	O
inflationary’	O
negation	O
(	O
negation	O
of	O
non-ground	O
atoms	O
)	O
.	O
</s>
<s>
Different	O
reasoning	B-Application
systems	I-Application
may	O
support	O
monotonic	O
or	O
non-monotonic	O
reasoning	O
,	O
stratification	O
and	O
other	O
logical	O
techniques	O
.	O
</s>
<s>
Many	O
reasoning	B-Application
systems	I-Application
provide	O
capabilities	O
for	O
reasoning	O
under	O
uncertainty	O
.	O
</s>
<s>
This	O
is	O
important	O
when	O
building	O
situated	B-General_Concept
reasoning	B-Application
agents	I-Application
which	O
must	O
deal	O
with	O
uncertain	O
representations	O
of	O
the	O
world	O
.	O
</s>
<s>
This	O
section	O
provides	O
a	O
non-exhaustive	O
and	O
informal	O
categorisation	O
of	O
common	O
types	O
of	O
reasoning	B-Application
system	I-Application
.	O
</s>
<s>
Constraint	B-Application
solvers	I-Application
solve	O
constraint	B-Application
satisfaction	I-Application
problems	I-Application
(	O
CSPs	O
)	O
.	O
</s>
<s>
They	O
support	O
constraint	B-Application
programming	I-Application
.	O
</s>
<s>
Constraint	B-Application
solvers	I-Application
use	O
search	B-Application
,	O
backtracking	B-Algorithm
and	O
constraint	B-Application
propagation	I-Application
techniques	O
to	O
find	O
solutions	O
and	O
determine	O
optimal	O
solutions	O
.	O
</s>
<s>
They	O
may	O
employ	O
forms	O
of	O
linear	B-Algorithm
and	O
nonlinear	B-Algorithm
programming	I-Algorithm
.	O
</s>
<s>
For	O
example	O
,	O
they	O
may	O
be	O
used	O
to	O
calculate	O
optimal	O
scheduling	B-Application
,	O
design	O
efficient	O
integrated	O
circuits	O
or	O
maximise	O
productivity	O
in	O
a	O
manufacturing	O
process	O
.	O
</s>
<s>
Theorem	B-Application
provers	I-Application
use	O
automated	O
reasoning	O
techniques	O
to	O
determine	O
proofs	O
of	O
mathematical	O
theorems	O
.	O
</s>
<s>
In	O
addition	O
to	O
academic	O
use	O
,	O
typical	O
applications	O
of	O
theorem	B-Application
provers	I-Application
include	O
verification	O
of	O
the	O
correctness	O
of	O
integrated	O
circuits	O
,	O
software	B-Application
programs	I-Application
,	O
engineering	O
designs	O
,	O
etc	O
.	O
</s>
<s>
Logic	B-Language
programs	I-Language
(	O
LPs	O
)	O
are	O
software	B-Application
programs	I-Application
written	O
using	O
programming	O
languages	O
whose	O
primitives	O
and	O
expressions	O
provide	O
direct	O
representations	O
of	O
constructs	O
drawn	O
from	O
mathematical	O
logic	O
.	O
</s>
<s>
An	O
example	O
of	O
a	O
general-purpose	O
logic	B-Language
programming	I-Language
language	I-Language
is	O
Prolog	B-Language
.	O
</s>
<s>
LPs	O
represent	O
the	O
direct	O
application	O
of	O
logic	B-Language
programming	I-Language
to	O
solve	O
problems	O
.	O
</s>
<s>
Logic	B-Language
programming	I-Language
is	O
characterised	O
by	O
highly	O
declarative	B-Language
approaches	O
based	O
on	O
formal	O
logic	O
,	O
and	O
has	O
wide	O
application	O
across	O
many	O
disciplines	O
.	O
</s>
<s>
A	O
common	O
approach	O
is	O
to	O
implement	O
production	B-Application
systems	I-Application
to	O
support	O
forward	O
or	O
backward	O
chaining	O
.	O
</s>
<s>
Deductive	B-Algorithm
classifiers	I-Algorithm
arose	O
slightly	O
later	O
than	O
rule-based	B-Language
systems	O
and	O
were	O
a	O
component	O
of	O
a	O
new	O
type	O
of	O
artificial	B-Application
intelligence	I-Application
knowledge	O
representation	O
tool	O
known	O
as	O
frame	O
languages	O
.	O
</s>
<s>
It	O
is	O
similar	O
to	O
the	O
object-oriented	B-Application
model	O
.	O
</s>
<s>
Unlike	O
object-oriented	B-Application
models	O
however	O
,	O
frame	O
languages	O
have	O
a	O
formal	O
semantics	O
based	O
on	O
first	O
order	O
logic	O
.	O
</s>
<s>
They	O
utilize	O
this	O
semantics	O
to	O
provide	O
input	O
to	O
the	O
deductive	B-Algorithm
classifier	I-Algorithm
.	O
</s>
<s>
The	O
classifier	O
in	O
turn	O
can	O
analyze	O
a	O
given	O
model	O
(	O
known	O
as	O
an	O
ontology	B-Language
)	O
and	O
determine	O
if	O
the	O
various	O
relations	O
described	O
in	O
the	O
model	O
are	O
consistent	O
.	O
</s>
<s>
If	O
the	O
ontology	B-Language
is	O
not	O
consistent	O
the	O
classifier	O
will	O
highlight	O
the	O
declarations	O
that	O
are	O
inconsistent	O
.	O
</s>
<s>
If	O
the	O
ontology	B-Language
is	O
consistent	O
the	O
classifier	O
can	O
then	O
do	O
further	O
reasoning	O
and	O
draw	O
additional	O
conclusions	O
about	O
the	O
relations	O
of	O
the	O
objects	O
in	O
the	O
ontology	B-Language
.	O
</s>
<s>
Classifiers	O
are	O
an	O
important	O
technology	O
in	O
analyzing	O
the	O
ontologies	B-Language
used	O
to	O
describe	O
models	O
in	O
the	O
Semantic	O
web	O
.	O
</s>
<s>
Learning	O
systems	O
search	B-Application
for	O
generalised	O
rules	O
or	O
functions	O
that	O
yield	O
results	O
in	O
line	O
with	O
observations	O
and	O
then	O
use	O
these	O
generalisations	O
to	O
control	O
future	O
behavior	O
.	O
</s>
<s>
A	O
procedural	B-Application
reasoning	I-Application
system	I-Application
(	O
PRS	O
)	O
uses	O
reasoning	O
techniques	O
to	O
select	O
plans	O
from	O
a	O
procedural	O
knowledge	O
base	O
.	O
</s>
