OAI/GroupTheory/PolycyclicRecognition/Geometry/LieWordDifference.lean

GitHub source file

7 declarations, 0 contain sorry, 0 declared as axioms

Finite differences of Lie words along the lower central series

The nonlinear part of a bracket polynomial raises the filtration also for finite differences, not just infinitesimal ones. This supports the explicit inverse of a BCH translation.

  1. theorem OAI.PolycyclicRecognition.lie_sub_lie_decomposition line 20
  2. theorem OAI.PolycyclicRecognition.evalBracketWord_sub_mem line 25
  3. theorem OAI.PolycyclicRecognition.evalBracketWord_mul_sub_mem_succ line 34
  4. def OAI.PolycyclicRecognition.wordLinearPart line 54

    Source documentation

    The degree-one part of a word as a linear map in its input letters.

    def wordLinearPart : FreeMagma I → (I → L) →ₗ[ℝ] L
      | .of i => LinearMap.proj i
      | .mul _ _ => 0
  5. def OAI.PolycyclicRecognition.finiteDynkinLinearPart line 58
  6. theorem OAI.PolycyclicRecognition.evalBracketWord_sub_linear_mem_succ line 63
  7. theorem OAI.PolycyclicRecognition.finiteDynkinPolynomial_sub_linear_mem_succ line 75