Registers, basis, and externally supplied source family

Let

The register $N$ is the normal qubit; $A$ is the antiqubit. For both registers, the basis values $0$ and $1$ are called bulge and disk, respectively. They are finite labels only.

The sole unknown parameter is the normalized source weight $\theta \in [0,1]$, defined by

Thus $\theta$ is the relative weight of the first source component, not an absolute injection rate.