Counting all bounded-dimensional protected spaces
Lax342547.SmallSubspaceCount · concepts/Lax342547/SmallSubspaceCount.lean · lax-342547
No public endorsements yet.
Loading review…
Sign in with ORCIDNatural Language Statement
Lemma
Padding an actual basis gives a generator encoding of every subspace of dimension at most r and the uniform count 2 to the ambient-dimension times r.
Concept map
Evidence
Lean source view on GitHub
| 1 | import Lax342547.FiniteLinearLaw |
| 2 | import Mathlib.LinearAlgebra.Basis.VectorSpace |
| 3 | |
| 4 | /-! |
| 5 | --- |
| 6 | title: Counting all bounded-dimensional protected spaces |
| 7 | type: lemma |
| 8 | --- |
| 9 | Padding an actual basis gives a generator encoding of every subspace of dimension at most r and the uniform count 2 to the ambient-dimension times r. |
| 10 | -/ |
| 11 | |
| 12 | namespace Lax342547.SmallSubspaceCount |
| 13 | |
| 14 | open Lax342547.MomentSpace |
| 15 | |
| 16 | axiom padded_generators {K V : Type} [Field K] [AddCommGroup V] [Module K V] |
| 17 | [FiniteDimensional K V] (S : Submodule K V) (r : ℕ) (hr : Module.finrank K S ≤ r) : |
| 18 | ∃ f : Fin r → V, Submodule.span K (Set.range f) = S |
| 19 | |
| 20 | axiom small_subspace_card {H : Type} [Fintype H] (r : ℕ) : |
| 21 | Nat.card {S : Submodule Binary (H → Binary) // Module.finrank Binary S ≤ r} ≤ |
| 22 | 2^(Fintype.card H*r) |
| 23 | |
| 24 | end Lax342547.SmallSubspaceCount |
| 25 |
Builds on
Used by
From Mathlib
Discussion
Ask a question or add context. Endorsements and structured flags are kept in the review panel above.
0 comments