Minimal associated primes

[HechtiDerLachs]

An attempt to make the specialized functionality in Singular for zero dimensional ideals available.

This seemed to be useful for @simonbrandhorst in some examples, but now I can't even get the tests to terminate. Let's see what the CI says.

@wdecker : The documentation reads as if only QQ was allowed as a coefficient ring. Do you remember whether this is the case? Because it seems to have run also over number fields.

[HechtiDerLachs]

@ederc : Could you have a look at the tests? I don't understand what's going wrong. But maybe minimal_primes now called singular_generators before and that lead to some false caching?

[simonbrandhorst]

Thanks for wrapping this @HechtiDerLachs !

[ederc]

Well, the tests fail because you try to apply assPrimes from Singular on a zero dimensional ideal over a finite field, but assPrimes assumes that the ideal lives over QQ. AFAIK there is a modular std call behind the scenes in assPrimes.

[HechtiDerLachs]

The problem I meant occured in an earlier test run. Some call to dim was complaining that singular_groebner_generators did not return a groebner basis. But it doesn't seem to be reproduced anymore; sorry for calling you.

But what you say about minAss is good to know. I will restrict the cases where it's called.

[HechtiDerLachs]

@ederc : Now the error is back, see this test.

[ederc]

There was a missing caching of the isGB flag if a GB was computed during small_generating_set. I pushed a fix to your branch.