Master enumeration of the space groups of : the list of with its affine and Sohncke bookkeeping
OpenLeanEval.Geometry.SpaceGroupsProblem.space_groups_master_classificationWork in with its Euclidean metric and let be the group of bijective affine isometries. A subgroup is crystallographic if (i) for every and every the set is finite, and (ii) contains translations by three linearly independent vectors. Write if for some invertible affine map , and if such a can be chosen with . Call a Sohncke group if every has .
The three classical counts — space-group types, affine classes, Sohncke types — are three readings of one and the same classification, and this statement packages them into a single assertion. It asks for a list
of crystallographic groups of together with two pieces of bookkeeping data about that list:
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The list is a complete irredundant set of representatives for . Every crystallographic group satisfies for some , and forces . This is the Fedorov–Schoenflies count of .
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A selection of representatives for . Every index satisfies for some , and forces . Since is coarser than , and every crystallographic group is -equivalent (hence -equivalent) to some member of the list, the selected members form a complete irredundant list for : the enantiomorphic pairs among the have been merged.
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An injection whose image is exactly the set of Sohncke members of the list, i.e. is a Sohncke group if and only if for some . Because the Sohncke condition is invariant under affine conjugacy, the Sohncke groups form a union of -classes, so these members form a complete irredundant list of the Sohncke groups up to .
Consequently this single statement implies each of space_groups_OP_classification (), space_groups_affine_classification () and space_groups_sohncke_classification (); those three deductions are supplied as proof-sketch reductions to this theorem, so the mission's frontier is the present statement alone.
Formalization note. CrystallographicGroup 3 is the subtype of crystallographic subgroups, AffOPEquivalent and AffinelyEquivalent are and , and IsOrientationPreservingIsom g says ; all are the mission's own definitions.
import Mathlib import Definitions.Def_LeanEval_SpaceGroups_Definitions
namespace LeanEval
namespace Geometry
namespace SpaceGroupsProblem
theorem space_groups_master_classification :
∃ f : Fin 230 → CrystallographicGroup 3,
(∀ G : CrystallographicGroup 3, ∃ i : Fin 230, AffOPEquivalent (f i).1 G.1) ∧
(∀ i j : Fin 230, AffOPEquivalent (f i).1 (f j).1 → i = j) ∧
(∃ s : Fin 219 → Fin 230,
(∀ i : Fin 230, ∃ k : Fin 219, AffinelyEquivalent (f (s k)).1 (f i).1) ∧
(∀ k l : Fin 219, AffinelyEquivalent (f (s k)).1 (f (s l)).1 → k = l)) ∧
(∃ t : Fin 65 → Fin 230, Function.Injective t ∧
∀ i : Fin 230,
(∀ g, g ∈ (f i).1 → IsOrientationPreservingIsom g) ↔ ∃ k : Fin 65, t k = i) := by
sorry
end SpaceGroupsProblem
end Geometry
end LeanEval