Let f be given.
rewrite the current goal using HXdef (from right to left).
An exact proof term for the current goal is HfX.
We prove the intermediate
claim HfiU2:
apply_fun f i ∈ U.
rewrite the current goal using Happ (from right to left).
An exact proof term for the current goal is HfiU.
Apply andI to the current goal.
Apply andI to the current goal.
An exact proof term for the current goal is Hi.
An exact proof term for the current goal is HUtop.
An exact proof term for the current goal is HfiU2.
Let f be given.
rewrite the current goal using HXdef (from left to right).
An exact proof term for the current goal is Hfprod.
We prove the intermediate
claim HfiU:
apply_fun f i ∈ U.
rewrite the current goal using Hpre_def (from left to right).
rewrite the current goal using Happ (from left to right).
An exact proof term for the current goal is HfiU.