OAI/Algebra/GroupRing/LoopTracks.lean
6 declarations, 0 contain sorry, 0 declared as axioms
- def
OAI.TorsionFreeZeroDivisors.LoopTracks.pathOfHomotopyline 15Source 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 … - def
OAI.TorsionFreeZeroDivisors.LoopTracks.homotopyOfPathline 21Source 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 … - lemma
OAI.TorsionFreeZeroDivisors.LoopTracks.homotopic_iff_joinedline 27 - def
OAI.TorsionFreeZeroDivisors.LoopTracks.piOneHomeoline 32 - def
OAI.TorsionFreeZeroDivisors.LoopTracks.uniqueLoopHomeoline 52 - lemma
OAI.TorsionFreeZeroDivisors.LoopTracks.loopGroup_commline 65Source 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 …