Legal programmes and accounting conventions

For this manuscript a sufficient frozen library contains: the explicitly defined ${U_B}^{†}$ and ${U_K}^{†}$ matrices, unitary extensions of $F$, single-qubit Clifford operations, Bell preparation, the two-qubit measurement used below, ordinary projective measurements, and explicit discards. A unitary extension of $F$ is fixed by completing its four columns with Gram–Schmidt in computational-basis order. Thus the finite library is determined by printed matrices, not by an unspecified synthesis oracle.