<s>
In	O
type	O
theory	O
and	O
functional	B-Language
programming	I-Language
,	O
a	O
stream	O
is	O
a	O
potentially	O
infinite	O
analog	O
of	O
a	O
list	O
,	O
given	O
by	O
the	O
coinductive	B-Application
definition	O
:	O
</s>
<s>
Generating	O
and	O
computing	O
with	O
streams	O
requires	O
lazy	O
evaluation	O
,	O
either	O
implicitly	O
in	O
a	O
lazily	O
evaluated	O
language	O
or	O
by	O
creating	O
and	O
forcing	O
thunks	B-Application
in	O
an	O
eager	O
language	O
.	O
</s>
<s>
In	O
total	B-Application
languages	I-Application
they	O
must	O
be	O
defined	O
as	O
codata	O
and	O
can	O
be	O
iterated	O
over	O
using	O
(	O
guarded	O
)	O
corecursion	B-Application
.	O
</s>
