The first of these was proved by Bernard Dwork; a completely different proof of the first two, via ℓ-adic cohomology, was given by Alexander Grothendieck.
Tazart dǎɣ təmtar atiwəsəkna as Bernard Dwork; tamətert təknat azalay ad tin sanatət azarnen, as tartit ən milhaw -adique, atiwəkfa as Alexander Grothendieck.