基于约束的频繁项集

有时我们并不关心所有的频繁项集，只想了解我们关心的。加约束条件去挖掘既灵活又可加快速度。

模式空间剪枝约束

Anti-monotonic: If constraint $c$ is violated, its further mining can be terminated

Monotonic: If $c$ is satisfied, no need to check $c$ again

Succinct: If the constraint $c$ can be enforced by directly manipulating the data

Convertible:$c$ can be converted to monotonic or anti-monotonic if items can be ordered in processing

数据空间剪枝约束

Data succinct: Data space can be pruned at the initial pattern mining process

Data anti-monotonic: If a transaction $t$ does not satisfy $c$ ,then $t$ can be pruned to reduce data processing effort