Feature #562
Subrings
Description
The notion of subrings looks promising. Investigate & implement (if appropriate).
Related issues
History
#1 Updated by John Abbott over 9 years ago
- Target version changed from CoCoALib-0.99534 Seoul14 to CoCoALib-1.0
#2 Updated by John Abbott over 3 years ago
- Related to Feature #1468: Adjoin indets to a poly ring added
#3 Updated by John Abbott over 3 years ago
Which sorts of subring would we like to represent?
- (A) in a polyring a subring generated by a subset of the indets
- (B) in a polyring the subring whose coeffs lie in a subring of the coeffring
- (C) combine (A) and (B)?
- (D) (for modular reduction) in QQ the subring of p-adic integers (i.e. p does not divide the denom)
- other ideas?
My idea is that a subring could be used as the domain of a ringhom; this means that it should be quick/easy to detect if a ringelem is in the subring.
Presumably we would need ome way to represent these subrings, and also a list of permitted operations on them.
The operations I foresee are: using them to specify the domain of a ringhom, and probably extracting the "big ring" from the subring.