<s>
In	O
computer	B-General_Concept
science	I-General_Concept
,	O
a	O
deterministic	B-General_Concept
algorithm	I-General_Concept
is	O
an	O
algorithm	O
that	O
,	O
given	O
a	O
particular	O
input	O
,	O
will	O
always	O
produce	O
the	O
same	O
output	O
,	O
with	O
the	O
underlying	O
machine	O
always	O
passing	O
through	O
the	O
same	O
sequence	O
of	O
states	O
.	O
</s>
<s>
Deterministic	B-General_Concept
algorithms	I-General_Concept
are	O
by	O
far	O
the	O
most	O
studied	O
and	O
familiar	O
kind	O
of	O
algorithm	O
,	O
as	O
well	O
as	O
one	O
of	O
the	O
most	O
practical	O
,	O
since	O
they	O
can	O
be	O
run	O
on	O
real	O
machines	O
efficiently	O
.	O
</s>
<s>
Formally	O
,	O
a	O
deterministic	B-General_Concept
algorithm	I-General_Concept
computes	O
a	O
mathematical	O
function	O
;	O
a	O
function	O
has	O
a	O
unique	O
value	O
for	O
any	O
input	O
in	O
its	O
domain	B-Algorithm
,	O
and	O
the	O
algorithm	O
is	O
a	O
process	O
that	O
produces	O
this	O
particular	O
value	O
as	O
output	O
.	O
</s>
<s>
Deterministic	B-General_Concept
algorithms	I-General_Concept
can	O
be	O
defined	O
in	O
terms	O
of	O
a	O
state	B-Architecture
machine	I-Architecture
:	O
a	O
state	O
describes	O
what	O
a	O
machine	O
is	O
doing	O
at	O
a	O
particular	O
instant	O
in	O
time	O
.	O
</s>
<s>
State	B-Architecture
machines	I-Architecture
pass	O
in	O
a	O
discrete	O
manner	O
from	O
one	O
state	O
to	O
another	O
.	O
</s>
<s>
Just	O
after	O
we	O
enter	O
the	O
input	O
,	O
the	O
machine	O
is	O
in	O
its	O
initial	O
state	O
or	O
start	B-Architecture
state	I-Architecture
.	O
</s>
<s>
Examples	O
of	O
particular	O
abstract	B-Application
machines	I-Application
which	O
are	O
deterministic	O
include	O
the	O
deterministic	B-Architecture
Turing	I-Architecture
machine	I-Architecture
and	O
deterministic	B-General_Concept
finite	I-General_Concept
automaton	I-General_Concept
.	O
</s>
<s>
For	O
this	O
reason	O
,	O
most	O
programming	O
languages	O
and	O
especially	O
functional	B-Language
programming	I-Language
languages	I-Language
make	O
an	O
effort	O
to	O
prevent	O
the	O
above	O
events	O
from	O
happening	O
except	O
under	O
controlled	O
conditions	O
.	O
</s>
<s>
The	O
prevalence	O
of	O
multi-core	B-Architecture
processors	I-Architecture
has	O
resulted	O
in	O
a	O
surge	O
of	O
interest	O
in	O
determinism	O
in	O
parallel	O
programming	O
and	O
challenges	O
of	O
non-determinism	O
have	O
been	O
well	O
documented	O
.	O
</s>
<s>
A	O
number	O
of	O
tools	O
to	O
help	O
deal	O
with	O
the	O
challenges	O
have	O
been	O
proposed	O
to	O
deal	O
with	O
deadlocks	B-Operating_System
and	O
race	B-Operating_System
conditions	I-Operating_System
.	O
</s>
<s>
The	O
behavior	O
of	O
a	O
card	O
shuffling	O
program	O
used	O
in	O
a	O
game	O
of	O
blackjack	B-Application
,	O
for	O
example	O
,	O
should	O
not	O
be	O
predictable	O
by	O
players	O
—	O
even	O
if	O
the	O
source	O
code	O
of	O
the	O
program	O
is	O
visible	O
.	O
</s>
<s>
The	O
use	O
of	O
a	O
pseudorandom	B-Algorithm
number	I-Algorithm
generator	I-Algorithm
is	O
often	O
not	O
sufficient	O
to	O
ensure	O
that	O
players	O
are	O
unable	O
to	O
predict	O
the	O
outcome	O
of	O
a	O
shuffle	O
.	O
</s>
<s>
These	O
problems	O
can	O
be	O
avoided	O
,	O
in	O
part	O
,	O
through	O
the	O
use	O
of	O
a	O
cryptographically	B-Algorithm
secure	I-Algorithm
pseudo-random	I-Algorithm
number	I-Algorithm
generator	I-Algorithm
,	O
but	O
it	O
is	O
still	O
necessary	O
for	O
an	O
unpredictable	O
random	B-Algorithm
seed	I-Algorithm
to	O
be	O
used	O
to	O
initialize	O
the	O
generator	O
.	O
</s>
<s>
The	O
mercury	B-Operating_System
logic-functional	O
programming	O
language	O
establishes	O
different	O
determinism	O
categories	O
for	O
predicate	O
modes	O
as	O
explained	O
in	O
the	O
reference	O
.	O
</s>
<s>
Haskell	B-Language
provides	O
several	O
mechanisms	O
:	O
</s>
<s>
In	O
Java	B-Language
,	O
the	O
null	O
reference	O
value	O
may	O
represent	O
an	O
unsuccessful	O
(	O
out-of-domain	O
)	O
result	O
.	O
</s>
