theorem
Function.Injective.pprod_map
{α : Sort u_1}
{β : Sort u_2}
{γ : Sort u_3}
{δ : Sort u_4}
{f : α → β}
{g : γ → δ}
(hf : Function.Injective f)
(hg : Function.Injective g)
:
Function.Injective fun x => { fst := f x.fst, snd := g x.snd }