The inverse limit of a family of -modules is the dual notion of a direct limit and is characterized by the following mapping property. For a directed set
and a family of
-modules
, let
be an inverse system.
is some
-module with some homomorphisms
, where for each
,
| (1) |
such that if there exists some -module
with homomorphisms
, where for each
,
| (2) |
then a unique homomorphism is induced and the above diagram commutes.
The inverse limit can be constructed as follows. For a given inverse system, , write
| (3) |