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Theorems · Theorem · group theory

alternatingGroup.isTrivialBlock_of_isBlock

∀ (α : Type u_1) [inst : Fintype α] [inst_1 : DecidableEq α] {B : Set α},
  MulAction.IsBlock (↥(alternatingGroup α)) B → MulAction.IsTrivialBlock B

The action of the alternating group has trivial blocks. This holds for any α, even when Nat.card α ≤ 2 and the action is not preprimitive, because it is not pretransitive.

Defined in
Mathlib.GroupTheory.GroupAction.MultipleTransitivity
Cited by
1 results in Mathlib
Foundations
Depth 107 from the axioms · uses propext, Classical.choice, Quot.sound
Assumes
FintypeDecidableEq

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