When indexed sum are nested through Sum involve a KroneckerDelta the scalar_indexed_sum_over_kronecker does not know how to handle it.
>>> i = IdxSym('i'); j = IdxSym('j')
>>> ket_i = BasisKet(FockIndex(i), hs=0)
>>> ket_j = BasisKet(FockIndex(j), hs=0)
>>> Sum(i)(Sum(j)(ket_i.dag() * ket_j))
Traceback (most recent call last):
File "<ipython-input-6-11142b06b2d0>", line 1, in <module>
Sum(i)(Sum(j)(ket_i.dag() * ket_j))
File "/Users/goerz/Documents/Programming/github/QNET/src/qnet/algebra/core/abstract_quantum_algebra.py", line 776, in sum
return term._indexed_sum_cls.create(term, idx_range)
File "/Users/goerz/Documents/Programming/github/QNET/src/qnet/algebra/core/scalar_algebra.py", line 861, in create
return super().create(term, *ranges)
File "/Users/goerz/Documents/Programming/github/QNET/src/qnet/algebra/core/abstract_algebra.py", line 115, in create
simplified = simplification(cls, args, kwargs)
File "/Users/goerz/Documents/Programming/github/QNET/src/qnet/algebra/core/algebraic_properties.py", line 558, in scalar_indexed_sum_over_kronecker
assert i in bound_symbols and j in bound_symbols
AssertionError
The solution is to handle the case where only one of i, j is an index of the sum (the sum can still be executed, so this is an easy fix). Once this is done, test_sum_instantiator can be updated to test this case.
When indexed sum are nested through
Suminvolve aKroneckerDeltathescalar_indexed_sum_over_kroneckerdoes not know how to handle it.The solution is to handle the case where only one of
i,jis an index of the sum (the sum can still be executed, so this is an easy fix). Once this is done,test_sum_instantiatorcan be updated to test this case.