Opened 6 years ago

Last modified 5 years ago

#14504 new defect

finite field coercion fails for extended fields

Reported by: llpamies Owned by: burcin
Priority: major Milestone: sage-6.4
Component: symbolics Keywords:
Cc: Merged in:
Authors: Reviewers:
Report Upstream: N/A Work issues:
Branch: Commit:
Dependencies: Stopgaps:

Description

The following code works:

sage: ff.<x>=GF(4)
sage: ff(x+1)

However, if we try to get the element from an expression it fails:

sage: o=var('o')
sage: ff.<x>=GF(4)            
sage: ff((x*o).coefficient(o))
TypeError: unable to coerce

This bug only happens for extended fields. You can try it by executing:

for fsize in [2,3,4,5,8]:
    ff.<x>=GF(fsize)
    o=var('o')
    e=(x+1)*o   
    e.coefficient(o)
    c = e.coefficient(o)
    try:
        print fsize, ff(c)
    except:
        print fsize, 'extended fields fail!'

Change History (5)

comment:1 Changed 6 years ago by ppurka

  • Cc punarbasu@… removed
  • Component changed from PLEASE CHANGE to symbolics
  • Milestone set to sage-5.10
  • Owner changed from tbd to burcin

comment:2 Changed 6 years ago by jdemeyer

  • Milestone changed from sage-5.11 to sage-5.12

comment:3 Changed 5 years ago by vbraun_spam

  • Milestone changed from sage-6.1 to sage-6.2

comment:4 Changed 5 years ago by vbraun_spam

  • Milestone changed from sage-6.2 to sage-6.3

comment:5 Changed 5 years ago by vbraun_spam

  • Milestone changed from sage-6.3 to sage-6.4
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