<s>
A	O
solver	B-Application
is	O
a	O
piece	O
of	O
mathematical	B-Application
software	I-Application
,	O
possibly	O
in	O
the	O
form	O
of	O
a	O
stand-alone	O
computer	B-Application
program	I-Application
or	O
as	O
a	O
software	B-Library
library	I-Library
,	O
that	O
'	O
solves	O
 '	O
a	O
mathematical	O
problem	O
.	O
</s>
<s>
A	O
solver	B-Application
takes	O
problem	O
descriptions	O
in	O
some	O
sort	O
of	O
generic	O
form	O
and	O
calculates	O
their	O
solution	O
.	O
</s>
<s>
In	O
a	O
solver	B-Application
,	O
the	O
emphasis	O
is	O
on	O
creating	O
a	O
program	O
or	O
library	O
that	O
can	O
easily	O
be	O
applied	O
to	O
other	O
problems	O
of	O
similar	O
type	O
.	O
</s>
<s>
Types	O
of	O
problems	O
with	O
existing	O
dedicated	O
solvers	B-Application
include	O
:	O
</s>
<s>
In	O
the	O
case	O
of	O
a	O
single	O
equation	O
,	O
the	O
"	O
solver	B-Application
"	O
is	O
more	O
appropriately	O
called	O
a	O
root-finding	O
algorithm	O
.	O
</s>
<s>
Systems	O
of	O
polynomial	O
equations	O
,	O
which	O
are	O
a	O
special	O
case	O
of	O
non	O
linear	O
systems	O
,	O
better	O
solved	O
by	O
specific	O
solvers	B-Application
.	O
</s>
<s>
The	O
General	O
Problem	O
Solver	B-Application
(	O
GPS	O
)	O
is	O
a	O
particular	O
computer	B-Application
program	I-Application
created	O
in	O
1957	O
by	O
Herbert	O
Simon	O
,	O
J	O
.	O
C	O
.	O
Shaw	O
,	O
and	O
Allen	O
Newell	O
intended	O
to	O
work	O
as	O
a	O
universal	O
problem	O
solver	B-Application
,	O
that	O
theoretically	O
can	O
be	O
used	O
to	O
solve	O
every	O
possible	O
problem	O
that	O
can	O
be	O
formalized	O
in	O
a	O
symbolic	O
system	O
,	O
given	O
the	O
right	O
input	O
configuration	O
.	O
</s>
<s>
It	O
was	O
the	O
first	O
computer	B-Application
program	I-Application
that	O
separated	O
its	O
knowledge	O
of	O
problems	O
(	O
in	O
the	O
form	O
of	O
domain	B-General_Concept
rules	O
)	O
from	O
its	O
strategy	O
of	O
how	O
to	O
solve	O
problems	O
(	O
as	O
a	O
general	O
search	O
engine	B-Application
)	O
.	O
</s>
<s>
General	O
solvers	B-Application
typically	O
use	O
an	O
architecture	O
similar	O
to	O
the	O
GPS	O
to	O
decouple	O
a	O
problem	O
's	O
definition	O
from	O
the	O
strategy	O
used	O
to	O
solve	O
it	O
.	O
</s>
<s>
The	O
advantage	O
in	O
this	O
decoupling	O
is	O
that	O
the	O
solver	B-Application
does	O
not	O
depend	O
on	O
the	O
details	O
of	O
any	O
particular	O
problem	O
instance	O
.	O
</s>
<s>
The	O
strategy	O
utilized	O
by	O
general	O
solvers	B-Application
was	O
based	O
on	O
a	O
general	O
algorithm	O
(	O
generally	O
based	O
on	O
backtracking	B-Algorithm
)	O
with	O
the	O
only	O
goal	O
of	O
completeness	O
.	O
</s>
<s>
Modern	O
solvers	B-Application
use	O
a	O
more	O
specialized	O
approach	O
that	O
takes	O
advantage	O
of	O
the	O
structure	O
of	O
the	O
problems	O
so	O
that	O
the	O
solver	B-Application
spends	O
as	O
little	O
time	O
as	O
possible	O
backtracking	B-Algorithm
.	O
</s>
<s>
Some	O
solvers	B-Application
implement	O
multiple	O
algorithms	O
.	O
</s>
