<s>
Lis	B-Language
(	O
Library	O
of	O
Iterative	B-Algorithm
Solvers	I-Algorithm
for	O
linear	O
systems	O
,	O
pronounced	O
 [ lis ] 	O
)	O
is	O
a	O
scalable	B-Architecture
parallel	B-Operating_System
software	B-Library
library	I-Library
for	O
solving	O
discretized	B-Algorithm
linear	O
equations	O
and	O
eigenvalue	O
problems	O
that	O
mainly	O
arise	O
in	O
the	O
numerical	B-General_Concept
solution	I-General_Concept
of	O
partial	O
differential	O
equations	O
by	O
using	O
iterative	B-Algorithm
methods	I-Algorithm
.	O
</s>
<s>
Although	O
it	O
is	O
designed	O
for	O
parallel	B-Operating_System
computers	I-Operating_System
,	O
the	O
library	O
can	O
be	O
used	O
without	O
being	O
conscious	O
of	O
parallel	B-Operating_System
processing	I-Operating_System
.	O
</s>
<s>
Lis	B-Language
provides	O
facilities	O
for	O
:	O
</s>
<s>
A	O
C	B-Language
program	I-Language
to	O
solve	O
the	O
linear	O
equation	O
is	O
written	O
as	O
follows	O
:	O
</s>
<s>
The	O
installation	O
of	O
Lis	B-Language
requires	O
a	O
C	B-Language
compiler	O
.	O
</s>
<s>
The	O
Fortran	B-Application
interface	O
requires	O
a	O
Fortran	B-Application
compiler	O
,	O
and	O
the	O
algebraic	O
multigrid	O
preconditioner	O
requires	O
a	O
Fortran	B-Application
90	O
compiler	O
.	O
</s>
<s>
For	O
parallel	B-Operating_System
computing	I-Operating_System
environments	O
,	O
an	O
OpenMP	B-Application
or	O
MPI	B-Application
library	O
is	O
required	O
.	O
</s>
<s>
Both	O
the	O
Matrix	B-Application
Market	I-Application
and	O
Harwell-Boeing	B-Application
formats	O
are	O
supported	O
to	O
import	O
and	O
export	O
user	O
data	O
.	O
</s>
