Library UniMath.MoreFoundations.Univalence

Additional results about univalence

Funextsec and toforallpaths are mutually inverses
Lemma funextsec_toforallpaths {T : UU} {P : T UU} {f g : t : T, P t} :
       (h : f = g), funextsec _ _ _ (toforallpaths _ _ _ h) = h.
Proof.
  intro h; exact (!homotinvweqweq0 (weqtoforallpaths _ _ _) h).
Defined.

Funextsec and toforallpaths are mutually inverses
Lemma toforallpaths_funextsec {T : UU} {P : T UU} {f g : t : T, P t} :
       (h : t : T, f t = g t), toforallpaths _ _ _ (funextsec _ _ _ h) = h.
Proof.
  intro h; exact (homotweqinvweq (weqtoforallpaths _ _ _) h).
Defined.