Pruning method 2
•
if a rule is discovered
before, we can prune
enumeration below this
node
–
Because all rules
below this node has
been discovered
before
–
For example, at node
34, if we found that
{aeh} has been
found, we can prune
off all branches
below it
{bls}
15
{l}
125
{a}
124
{a}
123
{al}
{aco}
{abclos}
{}
13
12
1
134
{f}
{}
{}
{}
{}
{a}
1245
1345
1235
1234
{}
345
12345
{aeh}
34
35
45
{q}
{acehoqt}
3
{}
245
{a}
2345
{bdfglqst}
5
{aefhpr}
4
{adehplr}
2
{dl}
25
{aehpr}
24
{aeh}
23
{}
235
{aeh}
234
{}
135
{}
145
{a}
14
{}
TT|
{3,4}