simp [finalVertex_homotopic_append [], ←finalVertexOnFreeGroup_natural]
case mk
α : Type
inst✝ : DecidableEq α
g : FreeGroup α
word : List (α × Bool)
⊢ mk (reducedWord (Quot.mk Step word)) = Quot.mk Step word
case mk
α : Type
inst✝ : DecidableEq α
g : FreeGroup α
word : List (α × Bool)
⊢ mk (finalVertex [] word) = mk word