Let F q = F p ( α ) {\displaystyle {}{\mathbb {F} }_{q}={\mathbb {F} }_{p}(\alpha )} , t ↦ α {\displaystyle {}t\mapsto \alpha } , deg ( α ) = d {\displaystyle {}\deg(\alpha )=d} . Set Q = 2 d − 1 {\displaystyle {}Q=2^{d-1}} . Then
![{\displaystyle {}xyf^{Q}\notin I^{[Q]}\,.}](https://wikimedia.org/api/rest_v1/media/math/render/svg/f03463ddcfba0e290d79ff8f53dd3b008ff8d810)