Fix formatting of mathematical notation in YAML

Author: phfaist

codes/quantum/properties/qecc_finite.yml

@@ -106,7 +106,7 @@ features:
     \(r\) over a quantum channel \(\mathcal{E}\) iff, for sufficiently large \(n\), \(m=\lfloor r n \rfloor\),
     and for all \(\epsilon>0\),
     \begin{align}
-      ||\mathcal{D}\mathcal{E}\mathcal{U}-I^{\otimes m}||_1\leq \epsilon
+      \lVert\mathcal{D}\mathcal{E}\mathcal{U}-I^{\otimes m}\rVert_1\leq \epsilon
     \end{align}
     for some encoding channel \(\mathcal{U}\) and some recovery channel \(\mathcal{D}\).
     The quantum capacity \(Q\) of \(\mathcal{E}\) is defined as the supremum over \(n\) of achievable transmission rates \cite{doi:10.1017/9781316848142}.