Decompose

Decompose a state into potentially smaller parts. Guarantees for any two states a and b that decompose(a).fold(b)(merge) == bmergea, i.e., merging the decomposed values into b has the same result as merging the full a into b (assuming b is normalized).

Note that the goal here is small individual storage size at reasonable computational cost. The results might not be minimal. The results might overlap. The result may be the empty sequence if a is the bottom value. Each result is <= the original value (according to the lattice).