Bi-Decomposition is a powerful approach for the synthesis of multi-level
combinational circuits because it utilizes the properties of the given
functions to find small circuits, with low power consumption and low delay.
Compact bi-decompositions restrict the variables in the support of the
decomposition functions as much as possible. Methods to find compact AND-,
OR-, or XOR-bi-decompositions for a given completely specified function are
well known. Lattices of Boolean Functions significantly increase the
possibilities to synthesize a minimal circuit. However, so far only methods
to find compact AND- or OR-bi-decompositions for lattices of Boolean functions
are known. This gap, i.e., a method to find a compact XOR-bi-decomposition
for a lattice of Boolean functions, has been closed by the approach
suggested in this paper.