<s>
An	O
ontology	B-Application
chart	I-Application
is	O
a	O
type	O
of	O
chart	O
used	O
in	O
semiotics	O
and	O
software	B-General_Concept
engineering	I-General_Concept
to	O
illustrate	O
an	O
ontology	O
.	O
</s>
<s>
The	O
nodes	O
of	O
an	O
ontology	B-Application
chart	I-Application
represent	O
universal	O
affordances	O
and	O
rarely	O
represent	O
particulars	O
.	O
</s>
<s>
The	O
exception	O
is	O
the	O
root	O
which	O
is	O
a	O
particular	O
agent	O
often	O
labelled	O
‘	O
society’	O
and	O
located	O
on	O
the	O
extreme	O
left	O
of	O
an	O
ontology	B-Application
chart	I-Application
.	O
</s>
<s>
The	O
root	O
is	O
often	O
dropped	O
in	O
practice	O
but	O
is	O
implied	O
in	O
every	O
ontology	B-Application
chart	I-Application
.	O
</s>
<s>
If	O
any	O
other	O
particular	O
is	O
present	O
in	O
an	O
ontology	B-Application
chart	I-Application
it	O
is	O
recognised	O
by	O
the	O
‘	O
#’	O
sign	O
prefix	O
and	O
upper	O
case	O
letters	O
.	O
</s>
<s>
In	O
our	O
ontology	B-Application
chart	I-Application
the	O
node	O
labelled	O
#IBM	O
is	O
a	O
particular	O
organisation	O
.	O
</s>
<s>
They	O
are	O
usually	O
dropped	O
from	O
the	O
ontology	B-Application
chart	I-Application
but	O
they	O
are	O
implied	O
and	O
obvious	O
.	O
</s>
<s>
No	O
ontology	B-Application
chart	I-Application
node	O
has	O
more	O
than	O
two	O
ontological	O
antecedents	O
.	O
</s>
<s>
Where	O
you	O
find	O
an	O
arc	O
on	O
the	O
ontology	B-Application
chart	I-Application
between	O
a	O
role	O
name	O
and	O
a	O
node	O
,	O
read	O
that	O
as	O
an	O
arc	O
between	O
the	O
right	O
hand	O
side	O
of	O
the	O
role	O
name	O
.	O
</s>
<s>
Mathematically	O
,	O
ontology	B-Application
charts	I-Application
are	O
a	O
graphical	O
representation	O
of	O
semi-lattice	O
structures	O
;	O
specifically	O
they	O
are	O
Hasse	O
diagrams	O
of	O
a	O
single	O
root	O
and	O
no	O
cycles	O
.	O
</s>
<s>
Because	O
ontology	B-Application
charts	I-Application
have	O
a	O
root	O
that	O
all	O
affordances	O
(	O
realisations/things	O
)	O
are	O
ultimately	O
dependent	O
upon	O
for	O
their	O
existence	O
,	O
they	O
are	O
graphical	O
representation	O
of	O
semi-lattices	O
.	O
</s>
