English
For a limit cone t of F, the hom component of limit isoLimitCone t followed by t.cone.π app j equals limit.π F j; this confirms the defining property of the isoLimitCone.
Русский
Для предела-конуса t функтор F, композиция limitIsoCone t.hom и t.cone.π j равна limit.π F j.
LaTeX
$$$(\\mathrm{limit}.isoLimitCone t).hom \\;\\circ\\; t.cone.π app j = \\mathrm{limit}.π F j$$$
Lean4
@[reassoc (attr := simp)]
theorem isoLimitCone_hom_π {F : J ⥤ C} [HasLimit F] (t : LimitCone F) (j : J) :
(limit.isoLimitCone t).hom ≫ t.cone.π.app j = limit.π F j :=
by
dsimp [limit.isoLimitCone, IsLimit.conePointUniqueUpToIso]
simp