Direct_Causal_Learning(DCL)
procedure remove_ parents(var PA);
i = 0;
repeat
for each Y∈PA
S = set of all sets A∈ PA{Y} such that | A|= i ;	// S contains the empty set Ø when i = 0;
A = first set in S;
while A is not null and Y ∈ PA	// A is null if there are no sets in S.
B = A ∪ {Y};
if deleting some node from B increase score(B;Z)
X = node whose deletion increases score the most;
if Y = X
remove Y from PA;
endif
endif
A = next set in S;	// A is null if there are no sets left in S.
endwhile
endfor
i=i + 1;
until | PA |≤ i or i > R;