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Bug #1130

SqFreeFactor: should it work over ZZ?

Added by Anna Maria Bigatti over 6 years ago. Updated almost 5 years ago.

Status:
In Progress
Priority:
Normal
Assignee:
-
Category:
Improving
Target version:
Start date:
29 Nov 2017
Due date:
% Done:

10%

Estimated time:
Spent time:

Description

this gives error (general code is for fields)

/**/  use P ::= ZZ[x,y,z];
/**/  indent(SqFreeFactor(5*x+1));
--> ERROR: Inexact division

but maybe the algorithm (and code) would work over ZZ?
Analyse and choose: either change the function or the documentation ;-)

History

#1 Updated by John Abbott almost 6 years ago

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

One potential problem is that strictly speaking the content must be factorized too, and it is costly to tell whether an integer is square-free.

I strongly suspect that one is almost never interested in the factorization of the content. JAA sees two approaches:
  1. put the content into RemainingFactor, and just consider the factorization of the polynomial part;
  2. factorize also the (integer) content; so if the caller is not interested in this part, then the content must be "removed" before calling.

Approach (1) is probably simpler to use, but is semantically "dodgy".
Approach (2) is semantically "cleaner", but probably more tedious to use.

Does KISS indicate approach (1)?

#2 Updated by John Abbott almost 6 years ago

  • Target version changed from CoCoALib-0.99600 to CoCoALib-0.99650 November 2019

#3 Updated by John Abbott almost 5 years ago

  • Target version changed from CoCoALib-0.99650 November 2019 to CoCoALib-1.0

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