<s>
In	O
computer	B-General_Concept
science	I-General_Concept
,	O
a	O
goal	B-Algorithm
node	I-Algorithm
is	O
a	O
node	B-Data_Structure
in	O
a	O
graph	O
that	O
meets	O
defined	O
criteria	O
for	O
success	O
or	O
termination	O
.	O
</s>
<s>
Heuristical	B-Algorithm
artificial	B-Application
intelligence	I-Application
algorithms	O
,	O
like	O
A*	B-Protocol
and	O
B*	B-Protocol
,	O
attempt	O
to	O
reach	O
such	O
nodes	O
in	O
optimal	O
time	O
by	O
defining	O
the	O
distance	O
to	O
the	O
goal	B-Algorithm
node	I-Algorithm
.	O
</s>
<s>
When	O
the	O
goal	B-Algorithm
node	I-Algorithm
is	O
reached	O
,	O
A*	B-Protocol
defines	O
the	O
distance	O
to	O
the	O
goal	B-Algorithm
node	I-Algorithm
as	O
0	O
and	O
all	O
other	O
nodes	O
 '	O
distances	O
as	O
positive	O
values	O
.	O
</s>
