MAFIA: PEP (Parent equivalence pruning)

PEP (Current node C, MFI) {

Expand all children using C.tail and reorder children by increasing support

Move children from C.tail to C.head with PEP pruning

For each item i in C.tail {

newNode = C union {i}

if newNode is frequent

PEP (newNode, MFI)

}

if (C is a leaf and C.head is not in MFI)

Add C.head to MFI

}