Fixed Ordering I
n
Restrict to networks consistent with a
fixed total
ordering
p
of the nodes*
n
A
®
B
Þ
A
p
B
n
Also each node X
i
has a set
W
i
of at most k possible
candidate parents**
n
Define:
Subsets of candidate parents of X
i
that
are consistent with the ordering
p
U
i,
p
=