I have a free module indexed by partition tuples. I construct twice what it is seemingly the same vector but the comparison fails:
sage: M = CombinatorialFreeModule(QQ, PartitionTuples(level=2))
sage: B = M.basis()
sage: p = Partition([])
sage: B[(p,p)] == M((p,p))
False
If I do this with partitions it's fine:
sage: M = CombinatorialFreeModule(QQ, PartitionTuples(level=1))
sage: B = M.basis()
sage: B[p] == M(p)
True
sage: