3 Representation of states and operators

Kets are represented by $n \times 1$ matrices, bras by $1 \times n$ matrices. The objects are represented in the computational basis. Bras and kets representing the same states are related by Maxima's conjugate transpose function ctranspose^$\dagger$ Density operators and other operators are represented by matrices. The tensor product is represented by the Kronecker product. There is no strong typing. You are responsible for knowing that a particular vector represents a state vector in a particular space. Below, we often substitute ``the operator'' for ``the matrix representing the operator''.