clarification subsystem

codes/quantum/qudits/subsystem/qudit_subsystem_stabilizer.yml

@@ -50,6 +50,7 @@ description: |
     \mathsf{G}&\to\left\langle \mathsf{G},\mathsf{F}\right\rangle ~.
   \end{split}
   \end{align}
+  The stabilizer group of the output subsystem code is a subgroup of that of the input code, \(\mathsf{Z}\left(\left\langle \mathsf{G},\mathsf{F}\right\rangle \right)\subseteq\mathsf{Z}\left(\mathsf{G}\right)\).
   When \(\mathsf{F}\) is a subgroup of the logical Pauli group, this is also called \textit{gauging}.
   If \(\mathsf{F}\) is itself a Pauli group of \(m\) logical qubits of the original subsystem code, then gauging those qubits is equivalent to treating them as gauge qubits.
   \end{defterm}