haruhisa-enomoto

"""A finite lattice is congruence-uniform (CU) if and only if it is constructed from a singleton
by iterating Day's doubling construction by intervals.
Using this fact, we can create a generator `CU_lattices_generator`
which yields finite CU lattices.
- Lattices appear without repetition (up to isomorphism),
- Every finite CU lattice appears by finitely many iterations.
"""

from collections import deque
singleton = LatticePoset({0: []})

haruhisa-enomoto

This is a sage code which computes a kamma map for a finite semidistributive lattice, which is a bijection from the set of join-irreducible elements to that of meet-irreducible ones.