<s>
In	O
mathematics	O
,	O
the	O
vertical	B-Algorithm
line	I-Algorithm
test	I-Algorithm
is	O
a	O
visual	O
way	O
to	O
determine	O
if	O
a	O
curve	O
is	O
a	O
graph	B-Application
of	I-Application
a	I-Application
function	I-Application
or	O
not	O
.	O
</s>
