A Shimura curve is a moduli scheme parametrize a certain family of abelian schemes.
After taking the formal completion, one can see that it is related to the formal scheme Omega hat
associated to the Drinfeld upper half plane. This is the well-known Cerednik-Drinfeld Theroem.
To prove this theorem, we need to develop a modular description of Omega hat via Deligne’s and
Drinfeld’s functor, and Cartier theory on formal modules is also used.