<s>
In	O
the	O
Unified	B-Language
Modeling	I-Language
Language	I-Language
(	O
UML	B-Language
)	O
,	O
a	O
Dependency	B-Application
is	O
a	O
relationship	O
that	O
shows	O
that	O
an	O
element	B-Language
,	O
or	O
set	O
of	O
elements	O
,	O
requires	O
other	O
model	O
elements	O
for	O
their	O
specification	O
or	O
implementation	O
.	O
</s>
<s>
The	O
element	B-Language
is	O
dependent	O
upon	O
the	O
independent	O
element	B-Language
,	O
called	O
the	O
supplier	O
.	O
</s>
<s>
Two	O
or	O
more	O
elements	O
in	O
this	O
relationship	O
are	O
called	O
tuples	B-Application
.	O
</s>
<s>
In	O
the	O
UML	B-Language
,	O
this	O
is	O
indicated	O
by	O
a	O
dashed	O
line	O
pointing	O
from	O
the	O
dependent	O
(	O
or	O
client	O
)	O
to	O
the	O
independent	O
(	O
or	O
supplier	O
)	O
element	B-Language
.	O
</s>
<s>
The	O
arrow	O
representing	O
a	O
Dependency	B-Application
specifies	O
the	O
direction	O
of	O
a	O
relationship	O
,	O
not	O
the	O
direction	O
of	O
a	O
process	O
.	O
</s>
<s>
UML	B-Language
-	O
defined	O
dependencies	B-Application
include	O
:	O
</s>
<s>
A	O
UML	B-Language
link	O
is	O
run-time	O
relationship	O
between	O
instances	O
of	O
classifiers	O
,	O
while	O
a	O
dependency	B-Application
is	O
a	O
model-time	O
relationship	O
between	O
definitions	O
.	O
</s>
<s>
A	O
uni-directional	O
link	O
only	O
requires	O
the	O
possibility	O
of	O
navigation	O
not	O
dependency	B-Application
.	O
</s>
<s>
Likewise	O
,	O
a	O
bi-directional	O
link	O
requires	O
that	O
both	O
instances	O
may	O
traverse	O
to	O
each	O
other	O
,	O
but	O
this	O
also	O
does	O
not	O
require	O
dependency	B-Application
.	O
</s>
<s>
However	O
,	O
after	O
the	O
traversal	O
of	O
the	O
association	O
,	O
if	O
some	O
property	O
of	O
the	O
target	O
instance	O
's	O
definition	O
is	O
accessed	O
,	O
such	O
as	O
an	O
operation	O
or	O
attribute	O
,	O
a	O
dependency	B-Application
is	O
created	O
.	O
</s>
