Noperthedron

8 Computational Step

Definition 51
#

We define rational approximations of the 90 noperthedron vertices by \(\lfloor x \cdot 10^{16} \rfloor /10^{16}\).

Theorem 52

nopertQ is a \(\kappa \)-rational approximation of the Noperthedron.

Proof
Theorem 53

There exists a valid solution table whose zeroth row covers

\begin{align*} \theta _1,\theta _2& \in [0,2\pi /15] \subset [0,0.42], \\ \varphi _1& \in [0,\pi ] \subset [0,3.15],\\ \varphi _2& \in [0,\pi /2] \subset [0,1.58],\\ \alpha & \in [-\pi /2,\pi /2] \subset [-1.58,1.58]. \end{align*}
Proof

By exhibiting the table and running the validity checking algorithm. Formalized as Noperthedron.NativeCaseAnalysis.solutionTable in the build-on-demand NativeCaseAnalysis library (checked with native_decide; a kernel-only KernelCaseAnalysis variant is in progress), which is kept out of the default build targets so that CI runs stay fast.

Theorem 54

If a global node in the solution tree is valid, then there is no Rupert solution for its interval.

Proof
Theorem 55

If a local node in the solution tree is valid, then there is no Rupert solution for its interval.

Proof

If we have a valid solution table, and in particular its \(i\)th row is valid, then there is no Rupert solution of the interval of its \(i\)th row.

Proof

By a mutual induction on the number of rows left in the table following the \(i\)th. This is because validity constrains each row to only refer to later entries. Appeal inductively to this same theorem if the row splits into other nodes in the tree, or appeal to Theorem 54 or Theorem 55) at the leaves.

Corollary 57

If we have a valid solution table, then there is no Rupert solution of the interval of its zeroth row.

Proof

Immediate special case of theorem 56.