English
A variant of congr_mk₁_map for ReflQuiver with explicit hx hy identifications ensures mk₁ equality.
Русский
Вариант congr_mk₁_map для ReflQuiver с явной идентификацией hx hy обеспечивает равенство mk₁.
LaTeX
$$$\text{same as above in a less syntactic form}$$$
Lean4
theorem mk_naturality_σ00 : toNerve₂.mk.naturalityProperty F (σ₂ (n := 0) 0) :=
by
ext x
refine Eq.trans ?_ (nerve.σ₀_mk₀_eq (C := C) (F.obj x)).symm
have := ReflPrefunctor.map_id F x
dsimp at this ⊢
rw [← this, ← OneTruncation₂.id_edge x]
fapply ReflPrefunctor.congr_mk₁_map
· simp [← FunctorToTypes.map_comp_apply, ← op_comp]
· simp [← FunctorToTypes.map_comp_apply, ← op_comp]
· aesop