def get_ground_set(self) -> _structure.Structure:
"""Return the :term:`ground set` of the lowest-level algebra of this :class:`Multiset`."""
if len(self.data) == 0:
return _structure.Structure()
elements_ground_set = _structure.Union(elem.get_ground_set()
for elem in self.data)
if len(elements_ground_set.data) == 1:
return _structure.PowerSet(
_structure.CartesianProduct(
_misc.get_single_iter_elem(elements_ground_set.data),
_structure.GenesisSetN()))
else:
return _structure.PowerSet(
_structure.CartesianProduct(elements_ground_set,
_structure.GenesisSetN()))
def get_absolute_ground_set() -> _structure.Structure:
"""Return the :term:`absolute ground set` of this :term:`algebra`."""
return _structure.PowerSet(
_structure.CartesianProduct(_relations.get_absolute_ground_set(),
_structure.GenesisSetN()))
def get_ground_set() -> _structure.Structure:
"""Return the :term:`ground set` of this :term:`algebra`."""
return _structure.PowerSet(
_structure.CartesianProduct(_structure.GenesisSetM(),
_structure.GenesisSetN()))