<s>
In	O
mathematics	O
,	O
the	O
domain	B-Algorithm
of	I-Algorithm
a	I-Algorithm
function	I-Algorithm
is	O
the	O
set	O
of	O
inputs	O
accepted	O
by	O
the	O
function	O
.	O
</s>
<s>
In	O
simpler	O
terms	O
,	O
the	O
laymen	O
explanation	O
of	O
the	O
domain	B-Algorithm
of	I-Algorithm
a	I-Algorithm
function	I-Algorithm
can	O
generally	O
be	O
thought	O
of	O
as	O
"	O
what	O
can	O
x	O
be	O
"	O
.	O
</s>
<s>
For	O
a	O
function	O
,	O
the	O
set	O
is	O
called	O
the	O
codomain	B-Algorithm
,	O
and	O
the	O
set	O
of	O
values	O
attained	O
by	O
the	O
function	O
(	O
which	O
is	O
a	O
subset	O
of	O
)	O
is	O
called	O
its	O
range	B-Algorithm
or	O
image	O
.	O
</s>
<s>
In	O
this	O
case	O
,	O
it	O
is	O
a	O
partial	B-Algorithm
function	I-Algorithm
,	O
and	O
the	O
set	O
of	O
real	O
numbers	O
on	O
which	O
the	O
formula	O
can	O
be	O
evaluated	O
to	O
a	O
real	O
number	O
is	O
called	O
the	O
natural	O
domain	O
or	O
domain	B-Algorithm
of	I-Algorithm
definition	I-Algorithm
of	O
.	O
</s>
<s>
In	O
many	O
contexts	O
,	O
a	O
partial	B-Algorithm
function	I-Algorithm
is	O
called	O
simply	O
a	O
function	O
,	O
and	O
its	O
natural	O
domain	O
is	O
called	O
simply	O
its	O
domain	O
.	O
</s>
<s>
The	O
piecewise	B-Algorithm
function	I-Algorithm
defined	O
by	O
has	O
as	O
its	O
natural	O
domain	O
the	O
set	O
of	O
real	O
numbers	O
.	O
</s>
<s>
Sometimes	O
such	O
a	O
domain	O
is	O
used	O
as	O
the	O
domain	B-Algorithm
of	I-Algorithm
a	I-Algorithm
function	I-Algorithm
,	O
although	O
functions	O
may	O
be	O
defined	O
on	O
more	O
general	O
sets	O
.	O
</s>
<s>
For	O
example	O
,	O
it	O
is	O
sometimes	O
convenient	O
in	O
set	O
theory	O
to	O
permit	O
the	O
domain	B-Algorithm
of	I-Algorithm
a	I-Algorithm
function	I-Algorithm
to	O
be	O
a	O
proper	O
class	O
,	O
in	O
which	O
case	O
there	O
is	O
formally	O
no	O
such	O
thing	O
as	O
a	O
triple	O
.	O
</s>
