<s>
In	O
mathematics	O
,	O
a	O
unitary	O
spider	B-Application
diagram	I-Application
adds	O
existential	O
points	O
to	O
an	O
Euler	B-Application
or	O
a	O
Venn	B-Application
diagram	I-Application
.	O
</s>
<s>
The	O
points	O
indicate	O
the	O
existence	O
of	O
an	O
attribute	O
described	O
by	O
the	O
intersection	O
of	O
contours	O
in	O
the	O
Euler	B-Application
diagram	I-Application
.	O
</s>
<s>
These	O
points	O
may	O
be	O
joined	O
together	O
forming	O
a	O
shape	O
like	O
a	O
spider	B-Protocol
.	O
</s>
<s>
A	O
spider	B-Application
diagram	I-Application
is	O
a	O
boolean	O
expression	O
involving	O
unitary	O
spider	B-Application
diagrams	I-Application
and	O
the	O
logical	O
symbols	O
.	O
</s>
<s>
For	O
example	O
,	O
it	O
may	O
consist	O
of	O
the	O
conjunction	O
of	O
two	O
spider	B-Application
diagrams	I-Application
,	O
the	O
disjunction	O
of	O
two	O
spider	B-Application
diagrams	I-Application
,	O
or	O
the	O
negation	O
of	O
a	O
spider	B-Application
diagram	I-Application
.	O
</s>
<s>
In	O
the	O
image	O
shown	O
,	O
the	O
following	O
conjunctions	O
are	O
apparent	O
from	O
the	O
Euler	B-Application
diagram	I-Application
.	O
</s>
<s>
In	O
the	O
universe	B-Algorithm
of	I-Algorithm
discourse	I-Algorithm
defined	O
by	O
this	O
Euler	B-Application
diagram	I-Application
,	O
in	O
addition	O
to	O
the	O
conjunctions	O
specified	O
above	O
,	O
all	O
possible	O
sets	O
from	O
A	O
through	O
B	O
and	O
D	O
through	O
G	O
are	O
available	O
separately	O
.	O
</s>
<s>
The	O
two	O
spiders	B-Protocol
in	O
the	O
example	O
correspond	O
to	O
the	O
following	O
logical	O
expressions	O
:	O
</s>
<s>
Red	O
spider	B-Protocol
:	O
</s>
<s>
Blue	O
spider	B-Protocol
:	O
</s>
