For a family of -modules indexed by a directed set , let
be an -module homomorphism. Call a direct system over when
1. for all .
2. When , .
For a family of -modules indexed by a directed set , let
be an -module homomorphism. Call a direct system over when
1. for all .
2. When , .
This entry contributed by Bart Snapp
Snapp, Bart. "Direct System." From MathWorld--A Wolfram Web Resource, created by Eric W. Weisstein. https://mathworld.wolfram.com/DirectSystem.html