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Feature #359

RingOf for list

Added by Anna Maria Bigatti almost 11 years ago. Updated over 8 years ago.

Status:
Closed
Priority:
Normal
Category:
CoCoA-4 function to be added
Start date:
27 May 2013
Due date:
% Done:

100%

Estimated time:
2.00 h
Spent time:

Description

It is often useful to know whether all elements in a list belong to the same ring.
A function of this kind was RingEnvSet in CoCoA-4.
It has been adjusted to CoCoA-5 as RingSet (see manual) but I'm not happy with the name: maybe it should be called RingsOf?

Moreover it is quite flexible (also deals with lists of lists, and with INT and RAT): too flexible?

History

#1 Updated by Anna Maria Bigatti almost 11 years ago

  • Target version set to CoCoA-5.0.9

#2 Updated by Anna Maria Bigatti almost 11 years ago

similar function in cocoalib is HasUniqueOwner

#3 Updated by John Abbott almost 11 years ago

Such a function would be helpful now. If we allow automatic conversion of RingElems in the future (seems quite likely) then what should the function do? Presumably it needs to identify the simplest "universal ring" for all the elements of the list.

There is also the question of what it should do if all elements are BigInt or BigRat (or even BigRat but all have denom 1)...?

#4 Updated by Anna Maria Bigatti almost 11 years ago

  • Category set to CoCoA-4 function to be added

#5 Updated by Anna Maria Bigatti over 10 years ago

  • Target version changed from CoCoA-5.0.9 to CoCoA-5.1.0 Easter14

#6 Updated by Anna Maria Bigatti almost 10 years ago

  • Status changed from New to In Progress
  • % Done changed from 0 to 10

Should this function work only for list of RINGELEM?
If so we can directly use HasUniqueOwner, otherwise is is very tedious to write...and how useful would that be?

#7 Updated by John Abbott almost 10 years ago

  • Target version changed from CoCoA-5.1.0 Easter14 to CoCoA-5.1.1 Seoul14

Want to discuss precise specifications of the fn.

#8 Updated by Anna Maria Bigatti over 9 years ago

  • % Done changed from 10 to 80

The function in CoCoA-5 is already done and called RingSet (see manual) but I'm not happy with the name: should I call it RingsOf?

#9 Updated by John Abbott over 9 years ago

  • Target version changed from CoCoA-5.1.1 Seoul14 to CoCoA-5.1.2 summer 2015

#10 Updated by Anna Maria Bigatti over 8 years ago

  • Status changed from In Progress to Feedback
  • Assignee set to Anna Maria Bigatti
  • % Done changed from 80 to 90
  • Estimated time set to 2.00 h

OK for "RingsOf". Changing manual and making "RingSet" obsolscent

#11 Updated by Anna Maria Bigatti over 8 years ago

  • Status changed from Feedback to Closed
  • % Done changed from 90 to 100

all done

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