Bug #1475
HilbertSeries: make into proper rational function
Description
It would be nicer if one could obtain a proper rational function as a hilbert series.
Related issues
History
#1 Updated by John Abbott almost 4 years ago
Andraschko's original email:
Arithmetic on Hilbert series or Hilbert functions. E.g. the code
/**/ S ::= QQ[x1,x2,x3,x4];
/**/ I := ideal(S,[RingElem(S,"x4")]);
/**/ H1 := HilbertSeries(R);
/**/ H2 := HilbertSeries(S/I);
/**/ H1 = H2;
produces two warnings that CoCoA is untagging the operators and then even says false. Also sth like H1 + H2 would be great. I have no idea whether it is possible to redefine operators as in C++, but even something like $hs.Equal(...)
or $hs.Add(...)
would be great.
#2 Updated by John Abbott almost 4 years ago
Bernhard points out that currently a "hilbert series" is a record.
Perhaps it is best then to add a new field which contains a proper ratfn representation of the HS.
In which field should the ratfn reside? Should there be a QQ like QQ[t] for num and den?
Or perhaps instead of QQ[t]?
#3 Updated by John Abbott over 2 years ago
- Target version changed from CoCoA-5.4.0 to CoCoA-5.4.2
#4 Updated by John Abbott about 1 year ago
- Related to Bug #1745: Printing of Hilbert series via indent added