OAI/Algebra/GroupRing/LoopTracks.lean

GitHub source file

6 declarations, 0 contain sorry, 0 declared as axioms

  1. def OAI.TorsionFreeZeroDivisors.LoopTracks.pathOfHomotopy line 15

    Source documentation

    A genuine relative path homotopy is a path in the compact-open path space.

    def pathOfHomotopy {p q : Path x y} (H : p.Homotopy q) : Path p q where
    …
  2. def OAI.TorsionFreeZeroDivisors.LoopTracks.homotopyOfPath line 21

    Source documentation

    Conversely: no quotient or merely formal track is used here.

    def homotopyOfPath {p q : Path x y} (h : Path p q) : p.Homotopy q where
    …
  3. lemma OAI.TorsionFreeZeroDivisors.LoopTracks.homotopic_iff_joined line 27
  4. def OAI.TorsionFreeZeroDivisors.LoopTracks.piOneHomeo line 32
  5. def OAI.TorsionFreeZeroDivisors.LoopTracks.uniqueLoopHomeo line 52
  6. lemma OAI.TorsionFreeZeroDivisors.LoopTracks.loopGroup_comm line 65

    Source documentation

    The loop-space fundamental group is genuinely commutative (Eckmann-Hilton). This is the coefficient group of two-cell homotopy-extension obstructions.

    lemma loopGroup_comm (x : X) : ∀a b : FundamentalGroup (Path x x) (Path.refl x), a*b=b*a := by
    …