https://physics.stackexchange.com/questions/276053/trouble-with-operator-sum-representation-of-a-quantum-operation/276158#comment1390158_276158
If any of you can find the value of $\mathbb{I}_A$ and the size of it please let me know.
If any of you can find the value of $\mathbb{I}_A$ and the size of it please let me know.